// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

// This is CodeMirror (http://codemirror.net), a code editor
// implemented in JavaScript on top of the browser's DOM.
//
// You can find some technical background for some of the code below
// at http://marijnhaverbeke.nl/blog/#cm-internals .

(function(mod) {
	if (typeof exports == "object" && typeof module == "object") // CommonJS
		module.exports = mod();
	else if (typeof define == "function" && define.amd) // AMD
		return define([], mod);
	else // Plain browser env
		this.CodeMirror = mod();
})(function() {
	"use strict";

	// BROWSER SNIFFING

	// Kludges for bugs and behavior differences that can't be feature
	// detected are enabled based on userAgent etc sniffing.

	var gecko = /gecko\/\d/i.test(navigator.userAgent);
	// ie_uptoN means Internet Explorer version N or lower
	var ie_upto10 = /MSIE \d/.test(navigator.userAgent);
	var ie_11up = /Trident\/(?:[7-9]|\d{2,})\..*rv:(\d+)/.exec(navigator.userAgent);
	var ie = ie_upto10 || ie_11up;
	var ie_version = ie && (ie_upto10 ? document.documentMode || 6 : ie_11up[1]);
	var webkit = /WebKit\//.test(navigator.userAgent);
	var qtwebkit = webkit && /Qt\/\d+\.\d+/.test(navigator.userAgent);
	var chrome = /Chrome\//.test(navigator.userAgent);
	var presto = /Opera\//.test(navigator.userAgent);
	var safari = /Apple Computer/.test(navigator.vendor);
	var khtml = /KHTML\//.test(navigator.userAgent);
	var mac_geMountainLion = /Mac OS X 1\d\D([8-9]|\d\d)\D/.test(navigator.userAgent);
	var phantom = /PhantomJS/.test(navigator.userAgent);

	var ios = /AppleWebKit/.test(navigator.userAgent) && /Mobile\/\w+/.test(navigator.userAgent);
	// This is woefully incomplete. Suggestions for alternative methods welcome.
	var mobile = ios || /Android|webOS|BlackBerry|Opera Mini|Opera Mobi|IEMobile/i.test(navigator.userAgent);
	var mac = ios || /Mac/.test(navigator.platform);
	var windows = /win/i.test(navigator.platform);

	var presto_version = presto && navigator.userAgent.match(/Version\/(\d*\.\d*)/);
	if (presto_version) presto_version = Number(presto_version[1]);
	if (presto_version && presto_version >= 15) { presto = false; webkit = true; }
	// Some browsers use the wrong event properties to signal cmd/ctrl on OS X
	var flipCtrlCmd = mac && (qtwebkit || presto && (presto_version == null || presto_version < 12.11));
	var captureRightClick = gecko || (ie && ie_version >= 9);

	// Optimize some code when these features are not used.
	var sawReadOnlySpans = false, sawCollapsedSpans = false;

	// EDITOR CONSTRUCTOR

	// A CodeMirror instance represents an editor. This is the object
	// that user code is usually dealing with.

	function CodeMirror(place, options) {
		if (!(this instanceof CodeMirror)) return new CodeMirror(place, options);

		this.options = options = options || {};
		// Determine effective options based on given values and defaults.
		copyObj(defaults, options, false);
		setGuttersForLineNumbers(options);

		var doc = options.value;
		if (typeof doc == "string") doc = new Doc(doc, options.mode);
		this.doc = doc;

		var display = this.display = new Display(place, doc);
		display.wrapper.CodeMirror = this;
		updateGutters(this);
		themeChanged(this);
		if (options.lineWrapping)
			this.display.wrapper.className += " CodeMirror-wrap";
		if (options.autofocus && !mobile) focusInput(this);

		this.state = {
			keyMaps: [],  // stores maps added by addKeyMap
			overlays: [], // highlighting overlays, as added by addOverlay
			modeGen: 0,   // bumped when mode/overlay changes, used to invalidate highlighting info
			overwrite: false, focused: false,
			suppressEdits: false, // used to disable editing during key handlers when in readOnly mode
			pasteIncoming: false, cutIncoming: false, // help recognize paste/cut edits in readInput
			draggingText: false,
			highlight: new Delayed() // stores highlight worker timeout
		};

		// Override magic textarea content restore that IE sometimes does
		// on our hidden textarea on reload
		if (ie && ie_version < 11) setTimeout(bind(resetInput, this, true), 20);

		registerEventHandlers(this);
		ensureGlobalHandlers();

		var cm = this;
		runInOp(this, function() {
			cm.curOp.forceUpdate = true;
			attachDoc(cm, doc);

			if ((options.autofocus && !mobile) || activeElt() == display.input)
				setTimeout(bind(onFocus, cm), 20);
			else
				onBlur(cm);

			for (var opt in optionHandlers) if (optionHandlers.hasOwnProperty(opt))
				optionHandlers[opt](cm, options[opt], Init);
			for (var i = 0; i < initHooks.length; ++i) initHooks[i](cm);
		});
	}

	// DISPLAY CONSTRUCTOR

	// The display handles the DOM integration, both for input reading
	// and content drawing. It holds references to DOM nodes and
	// display-related state.

	function Display(place, doc) {
		var d = this;

		// The semihidden textarea that is focused when the editor is
		// focused, and receives input.
		var input = d.input = elt("textarea", null, null, "position: absolute; padding: 0; width: 1px; height: 1em; outline: none");
		// The textarea is kept positioned near the cursor to prevent the
		// fact that it'll be scrolled into view on input from scrolling
		// our fake cursor out of view. On webkit, when wrap=off, paste is
		// very slow. So make the area wide instead.
		if (webkit) input.style.width = "1000px";
		else input.setAttribute("wrap", "off");
		// If border: 0; -- iOS fails to open keyboard (issue #1287)
		if (ios) input.style.border = "1px solid black";
		input.setAttribute("autocorrect", "off"); input.setAttribute("autocapitalize", "off"); input.setAttribute("spellcheck", "false");

		// Wraps and hides input textarea
		d.inputDiv = elt("div", [input], null, "overflow: hidden; position: relative; width: 3px; height: 0px;");
		// The fake scrollbar elements.
		d.scrollbarH = elt("div", [elt("div", null, null, "height: 100%; min-height: 1px")], "CodeMirror-hscrollbar");
		d.scrollbarV = elt("div", [elt("div", null, null, "min-width: 1px")], "CodeMirror-vscrollbar");
		// Covers bottom-right square when both scrollbars are present.
		d.scrollbarFiller = elt("div", null, "CodeMirror-scrollbar-filler");
		// Covers bottom of gutter when coverGutterNextToScrollbar is on
		// and h scrollbar is present.
		d.gutterFiller = elt("div", null, "CodeMirror-gutter-filler");
		// Will contain the actual code, positioned to cover the viewport.
		d.lineDiv = elt("div", null, "CodeMirror-code");
		// Elements are added to these to represent selection and cursors.
		d.selectionDiv = elt("div", null, null, "position: relative; z-index: 1");
		d.cursorDiv = elt("div", null, "CodeMirror-cursors");
		// A visibility: hidden element used to find the size of things.
		d.measure = elt("div", null, "CodeMirror-measure");
		// When lines outside of the viewport are measured, they are drawn in this.
		d.lineMeasure = elt("div", null, "CodeMirror-measure");
		// Wraps everything that needs to exist inside the vertically-padded coordinate system
		d.lineSpace = elt("div", [d.measure, d.lineMeasure, d.selectionDiv, d.cursorDiv, d.lineDiv],
			null, "position: relative; outline: none");
		// Moved around its parent to cover visible view.
		d.mover = elt("div", [elt("div", [d.lineSpace], "CodeMirror-lines")], null, "position: relative");
		// Set to the height of the document, allowing scrolling.
		d.sizer = elt("div", [d.mover], "CodeMirror-sizer");
		// Behavior of elts with overflow: auto and padding is
		// inconsistent across browsers. This is used to ensure the
		// scrollable area is big enough.
		d.heightForcer = elt("div", null, null, "position: absolute; height: " + scrollerCutOff + "px; width: 1px;");
		// Will contain the gutters, if any.
		d.gutters = elt("div", null, "CodeMirror-gutters");
		d.lineGutter = null;
		// Actual scrollable element.
		d.scroller = elt("div", [d.sizer, d.heightForcer, d.gutters], "CodeMirror-scroll");
		d.scroller.setAttribute("tabIndex", "-1");
		// The element in which the editor lives.
		d.wrapper = elt("div", [d.inputDiv, d.scrollbarH, d.scrollbarV,
			d.scrollbarFiller, d.gutterFiller, d.scroller], "CodeMirror");

		// Work around IE7 z-index bug (not perfect, hence IE7 not really being supported)
		if (ie && ie_version < 8) { d.gutters.style.zIndex = -1; d.scroller.style.paddingRight = 0; }
		// Needed to hide big blue blinking cursor on Mobile Safari
		if (ios) input.style.width = "0px";
		if (!webkit) d.scroller.draggable = true;
		// Needed to handle Tab key in KHTML
		if (khtml) { d.inputDiv.style.height = "1px"; d.inputDiv.style.position = "absolute"; }
		// Need to set a minimum width to see the scrollbar on IE7 (but must not set it on IE8).
		if (ie && ie_version < 8) d.scrollbarH.style.minHeight = d.scrollbarV.style.minWidth = "18px";

		if (place.appendChild) place.appendChild(d.wrapper);
		else place(d.wrapper);

		// Current rendered range (may be bigger than the view window).
		d.viewFrom = d.viewTo = doc.first;
		// Information about the rendered lines.
		d.view = [];
		// Holds info about a single rendered line when it was rendered
		// for measurement, while not in view.
		d.externalMeasured = null;
		// Empty space (in pixels) above the view
		d.viewOffset = 0;
		d.lastSizeC = 0;
		d.updateLineNumbers = null;

		// Used to only resize the line number gutter when necessary (when
		// the amount of lines crosses a boundary that makes its width change)
		d.lineNumWidth = d.lineNumInnerWidth = d.lineNumChars = null;
		// See readInput and resetInput
		d.prevInput = "";
		// Set to true when a non-horizontal-scrolling line widget is
		// added. As an optimization, line widget aligning is skipped when
		// this is false.
		d.alignWidgets = false;
		// Flag that indicates whether we expect input to appear real soon
		// now (after some event like 'keypress' or 'input') and are
		// polling intensively.
		d.pollingFast = false;
		// Self-resetting timeout for the poller
		d.poll = new Delayed();

		d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;

		// Tracks when resetInput has punted to just putting a short
		// string into the textarea instead of the full selection.
		d.inaccurateSelection = false;

		// Tracks the maximum line length so that the horizontal scrollbar
		// can be kept static when scrolling.
		d.maxLine = null;
		d.maxLineLength = 0;
		d.maxLineChanged = false;

		// Used for measuring wheel scrolling granularity
		d.wheelDX = d.wheelDY = d.wheelStartX = d.wheelStartY = null;

		// True when shift is held down.
		d.shift = false;

		// Used to track whether anything happened since the context menu
		// was opened.
		d.selForContextMenu = null;
	}

	// STATE UPDATES

	// Used to get the editor into a consistent state again when options change.

	function loadMode(cm) {
		cm.doc.mode = CodeMirror.getMode(cm.options, cm.doc.modeOption);
		resetModeState(cm);
	}

	function resetModeState(cm) {
		cm.doc.iter(function(line) {
			if (line.stateAfter) line.stateAfter = null;
			if (line.styles) line.styles = null;
		});
		cm.doc.frontier = cm.doc.first;
		startWorker(cm, 100);
		cm.state.modeGen++;
		if (cm.curOp) regChange(cm);
	}

	function wrappingChanged(cm) {
		if (cm.options.lineWrapping) {
			addClass(cm.display.wrapper, "CodeMirror-wrap");
			cm.display.sizer.style.minWidth = "";
		} else {
			rmClass(cm.display.wrapper, "CodeMirror-wrap");
			findMaxLine(cm);
		}
		estimateLineHeights(cm);
		regChange(cm);
		clearCaches(cm);
		setTimeout(function(){updateScrollbars(cm);}, 100);
	}

	// Returns a function that estimates the height of a line, to use as
	// first approximation until the line becomes visible (and is thus
	// properly measurable).
	function estimateHeight(cm) {
		var th = textHeight(cm.display), wrapping = cm.options.lineWrapping;
		var perLine = wrapping && Math.max(5, cm.display.scroller.clientWidth / charWidth(cm.display) - 3);
		return function(line) {
			if (lineIsHidden(cm.doc, line)) return 0;

			var widgetsHeight = 0;
			if (line.widgets) for (var i = 0; i < line.widgets.length; i++) {
				if (line.widgets[i].height) widgetsHeight += line.widgets[i].height;
			}

			if (wrapping)
				return widgetsHeight + (Math.ceil(line.text.length / perLine) || 1) * th;
			else
				return widgetsHeight + th;
		};
	}

	function estimateLineHeights(cm) {
		var doc = cm.doc, est = estimateHeight(cm);
		doc.iter(function(line) {
			var estHeight = est(line);
			if (estHeight != line.height) updateLineHeight(line, estHeight);
		});
	}

	function keyMapChanged(cm) {
		var map = keyMap[cm.options.keyMap], style = map.style;
		cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-keymap-\S+/g, "") +
			(style ? " cm-keymap-" + style : "");
	}

	function themeChanged(cm) {
		cm.display.wrapper.className = cm.display.wrapper.className.replace(/\s*cm-s-\S+/g, "") +
			cm.options.theme.replace(/(^|\s)\s*/g, " cm-s-");
		clearCaches(cm);
	}

	function guttersChanged(cm) {
		updateGutters(cm);
		regChange(cm);
		setTimeout(function(){alignHorizontally(cm);}, 20);
	}

	// Rebuild the gutter elements, ensure the margin to the left of the
	// code matches their width.
	function updateGutters(cm) {
		var gutters = cm.display.gutters, specs = cm.options.gutters;
		removeChildren(gutters);
		for (var i = 0; i < specs.length; ++i) {
			var gutterClass = specs[i];
			var gElt = gutters.appendChild(elt("div", null, "CodeMirror-gutter " + gutterClass));
			if (gutterClass == "CodeMirror-linenumbers") {
				cm.display.lineGutter = gElt;
				gElt.style.width = (cm.display.lineNumWidth || 1) + "px";
			}
		}
		gutters.style.display = i ? "" : "none";
		updateGutterSpace(cm);
	}

	function updateGutterSpace(cm) {
		var width = cm.display.gutters.offsetWidth;
		cm.display.sizer.style.marginLeft = width + "px";
		cm.display.scrollbarH.style.left = cm.options.fixedGutter ? width + "px" : 0;
	}

	// Compute the character length of a line, taking into account
	// collapsed ranges (see markText) that might hide parts, and join
	// other lines onto it.
	function lineLength(line) {
		if (line.height == 0) return 0;
		var len = line.text.length, merged, cur = line;
		while (merged = collapsedSpanAtStart(cur)) {
			var found = merged.find(0, true);
			cur = found.from.line;
			len += found.from.ch - found.to.ch;
		}
		cur = line;
		while (merged = collapsedSpanAtEnd(cur)) {
			var found = merged.find(0, true);
			len -= cur.text.length - found.from.ch;
			cur = found.to.line;
			len += cur.text.length - found.to.ch;
		}
		return len;
	}

	// Find the longest line in the document.
	function findMaxLine(cm) {
		var d = cm.display, doc = cm.doc;
		d.maxLine = getLine(doc, doc.first);
		d.maxLineLength = lineLength(d.maxLine);
		d.maxLineChanged = true;
		doc.iter(function(line) {
			var len = lineLength(line);
			if (len > d.maxLineLength) {
				d.maxLineLength = len;
				d.maxLine = line;
			}
		});
	}

	// Make sure the gutters options contains the element
	// "CodeMirror-linenumbers" when the lineNumbers option is true.
	function setGuttersForLineNumbers(options) {
		var found = indexOf(options.gutters, "CodeMirror-linenumbers");
		if (found == -1 && options.lineNumbers) {
			options.gutters = options.gutters.concat(["CodeMirror-linenumbers"]);
		} else if (found > -1 && !options.lineNumbers) {
			options.gutters = options.gutters.slice(0);
			options.gutters.splice(found, 1);
		}
	}

	// SCROLLBARS

	function hScrollbarTakesSpace(cm) {
		return cm.display.scroller.clientHeight - cm.display.wrapper.clientHeight < scrollerCutOff - 3;
	}

	// Prepare DOM reads needed to update the scrollbars. Done in one
	// shot to minimize update/measure roundtrips.
	function measureForScrollbars(cm) {
		var scroll = cm.display.scroller;
		return {
			clientHeight: scroll.clientHeight,
			barHeight: cm.display.scrollbarV.clientHeight,
			scrollWidth: scroll.scrollWidth, clientWidth: scroll.clientWidth,
			hScrollbarTakesSpace: hScrollbarTakesSpace(cm),
			barWidth: cm.display.scrollbarH.clientWidth,
			docHeight: Math.round(cm.doc.height + paddingVert(cm.display))
		};
	}

	// Re-synchronize the fake scrollbars with the actual size of the
	// content.
	function updateScrollbars(cm, measure) {
		if (!measure) measure = measureForScrollbars(cm);
		var d = cm.display, sWidth = scrollbarWidth(d.measure);
		var scrollHeight = measure.docHeight + scrollerCutOff;
		var needsH = measure.scrollWidth > measure.clientWidth;
		if (needsH && measure.scrollWidth <= measure.clientWidth + 1 &&
			sWidth > 0 && !measure.hScrollbarTakesSpace)
			needsH = false; // (Issue #2562)
		var needsV = scrollHeight > measure.clientHeight;

		if (needsV) {
			d.scrollbarV.style.display = "block";
			d.scrollbarV.style.bottom = needsH ? sWidth + "px" : "0";
			// A bug in IE8 can cause this value to be negative, so guard it.
			d.scrollbarV.firstChild.style.height =
				Math.max(0, scrollHeight - measure.clientHeight + (measure.barHeight || d.scrollbarV.clientHeight)) + "px";
		} else {
			d.scrollbarV.style.display = "";
			d.scrollbarV.firstChild.style.height = "0";
		}
		if (needsH) {
			d.scrollbarH.style.display = "block";
			d.scrollbarH.style.right = needsV ? sWidth + "px" : "0";
			d.scrollbarH.firstChild.style.width =
				(measure.scrollWidth - measure.clientWidth + (measure.barWidth || d.scrollbarH.clientWidth)) + "px";
		} else {
			d.scrollbarH.style.display = "";
			d.scrollbarH.firstChild.style.width = "0";
		}
		if (needsH && needsV) {
			d.scrollbarFiller.style.display = "block";
			d.scrollbarFiller.style.height = d.scrollbarFiller.style.width = sWidth + "px";
		} else d.scrollbarFiller.style.display = "";
		if (needsH && cm.options.coverGutterNextToScrollbar && cm.options.fixedGutter) {
			d.gutterFiller.style.display = "block";
			d.gutterFiller.style.height = sWidth + "px";
			d.gutterFiller.style.width = d.gutters.offsetWidth + "px";
		} else d.gutterFiller.style.display = "";

		if (!cm.state.checkedOverlayScrollbar && measure.clientHeight > 0) {
			if (sWidth === 0) {
				var w = mac && !mac_geMountainLion ? "12px" : "18px";
				d.scrollbarV.style.minWidth = d.scrollbarH.style.minHeight = w;
				var barMouseDown = function(e) {
					if (e_target(e) != d.scrollbarV && e_target(e) != d.scrollbarH)
						operation(cm, onMouseDown)(e);
				};
				on(d.scrollbarV, "mousedown", barMouseDown);
				on(d.scrollbarH, "mousedown", barMouseDown);
			}
			cm.state.checkedOverlayScrollbar = true;
		}
	}

	// Compute the lines that are visible in a given viewport (defaults
	// the the current scroll position). viewPort may contain top,
	// height, and ensure (see op.scrollToPos) properties.
	function visibleLines(display, doc, viewPort) {
		var top = viewPort && viewPort.top != null ? Math.max(0, viewPort.top) : display.scroller.scrollTop;
		top = Math.floor(top - paddingTop(display));
		var bottom = viewPort && viewPort.bottom != null ? viewPort.bottom : top + display.wrapper.clientHeight;

		var from = lineAtHeight(doc, top), to = lineAtHeight(doc, bottom);
		// Ensure is a {from: {line, ch}, to: {line, ch}} object, and
		// forces those lines into the viewport (if possible).
		if (viewPort && viewPort.ensure) {
			var ensureFrom = viewPort.ensure.from.line, ensureTo = viewPort.ensure.to.line;
			if (ensureFrom < from)
				return {from: ensureFrom,
					to: lineAtHeight(doc, heightAtLine(getLine(doc, ensureFrom)) + display.wrapper.clientHeight)};
			if (Math.min(ensureTo, doc.lastLine()) >= to)
				return {from: lineAtHeight(doc, heightAtLine(getLine(doc, ensureTo)) - display.wrapper.clientHeight),
					to: ensureTo};
		}
		return {from: from, to: Math.max(to, from + 1)};
	}

	// LINE NUMBERS

	// Re-align line numbers and gutter marks to compensate for
	// horizontal scrolling.
	function alignHorizontally(cm) {
		var display = cm.display, view = display.view;
		if (!display.alignWidgets && (!display.gutters.firstChild || !cm.options.fixedGutter)) return;
		var comp = compensateForHScroll(display) - display.scroller.scrollLeft + cm.doc.scrollLeft;
		var gutterW = display.gutters.offsetWidth, left = comp + "px";
		for (var i = 0; i < view.length; i++) if (!view[i].hidden) {
			if (cm.options.fixedGutter && view[i].gutter)
				view[i].gutter.style.left = left;
			var align = view[i].alignable;
			if (align) for (var j = 0; j < align.length; j++)
				align[j].style.left = left;
		}
		if (cm.options.fixedGutter)
			display.gutters.style.left = (comp + gutterW) + "px";
	}

	// Used to ensure that the line number gutter is still the right
	// size for the current document size. Returns true when an update
	// is needed.
	function maybeUpdateLineNumberWidth(cm) {
		if (!cm.options.lineNumbers) return false;
		var doc = cm.doc, last = lineNumberFor(cm.options, doc.first + doc.size - 1), display = cm.display;
		if (last.length != display.lineNumChars) {
			var test = display.measure.appendChild(elt("div", [elt("div", last)],
				"CodeMirror-linenumber CodeMirror-gutter-elt"));
			var innerW = test.firstChild.offsetWidth, padding = test.offsetWidth - innerW;
			display.lineGutter.style.width = "";
			display.lineNumInnerWidth = Math.max(innerW, display.lineGutter.offsetWidth - padding);
			display.lineNumWidth = display.lineNumInnerWidth + padding;
			display.lineNumChars = display.lineNumInnerWidth ? last.length : -1;
			display.lineGutter.style.width = display.lineNumWidth + "px";
			updateGutterSpace(cm);
			return true;
		}
		return false;
	}

	function lineNumberFor(options, i) {
		return String(options.lineNumberFormatter(i + options.firstLineNumber));
	}

	// Computes display.scroller.scrollLeft + display.gutters.offsetWidth,
	// but using getBoundingClientRect to get a sub-pixel-accurate
	// result.
	function compensateForHScroll(display) {
		return display.scroller.getBoundingClientRect().left - display.sizer.getBoundingClientRect().left;
	}

	// DISPLAY DRAWING

	// Updates the display, selection, and scrollbars, using the
	// information in display.view to find out which nodes are no longer
	// up-to-date. Tries to bail out early when no changes are needed,
	// unless forced is true.
	// Returns true if an actual update happened, false otherwise.
	function updateDisplay(cm, viewPort, forced) {
		var oldFrom = cm.display.viewFrom, oldTo = cm.display.viewTo, updated;
		var visible = visibleLines(cm.display, cm.doc, viewPort);
		for (var first = true;; first = false) {
			var oldWidth = cm.display.scroller.clientWidth;
			if (!updateDisplayInner(cm, visible, forced)) break;
			updated = true;

			// If the max line changed since it was last measured, measure it,
			// and ensure the document's width matches it.
			if (cm.display.maxLineChanged && !cm.options.lineWrapping)
				adjustContentWidth(cm);

			var barMeasure = measureForScrollbars(cm);
			updateSelection(cm);
			setDocumentHeight(cm, barMeasure);
			updateScrollbars(cm, barMeasure);
			if (webkit && cm.options.lineWrapping)
				checkForWebkitWidthBug(cm, barMeasure); // (Issue #2420)
			if (webkit && barMeasure.scrollWidth > barMeasure.clientWidth &&
				barMeasure.scrollWidth < barMeasure.clientWidth + 1 &&
				!hScrollbarTakesSpace(cm))
				updateScrollbars(cm); // (Issue #2562)
			if (first && cm.options.lineWrapping && oldWidth != cm.display.scroller.clientWidth) {
				forced = true;
				continue;
			}
			forced = false;

			// Clip forced viewport to actual scrollable area.
			if (viewPort && viewPort.top != null)
				viewPort = {top: Math.min(barMeasure.docHeight - scrollerCutOff - barMeasure.clientHeight, viewPort.top)};
			// Updated line heights might result in the drawn area not
			// actually covering the viewport. Keep looping until it does.
			visible = visibleLines(cm.display, cm.doc, viewPort);
			if (visible.from >= cm.display.viewFrom && visible.to <= cm.display.viewTo)
				break;
		}

		cm.display.updateLineNumbers = null;
		if (updated) {
			signalLater(cm, "update", cm);
			if (cm.display.viewFrom != oldFrom || cm.display.viewTo != oldTo)
				signalLater(cm, "viewportChange", cm, cm.display.viewFrom, cm.display.viewTo);
		}
		return updated;
	}

	// Does the actual updating of the line display. Bails out
	// (returning false) when there is nothing to be done and forced is
	// false.
	function updateDisplayInner(cm, visible, forced) {
		var display = cm.display, doc = cm.doc;
		if (!display.wrapper.offsetWidth) {
			resetView(cm);
			return;
		}

		// Bail out if the visible area is already rendered and nothing changed.
		if (!forced && visible.from >= display.viewFrom && visible.to <= display.viewTo &&
			(display.updateLineNumbers == null || display.updateLineNumbers >= display.viewTo) &&
			countDirtyView(cm) == 0)
			return;

		if (maybeUpdateLineNumberWidth(cm))
			resetView(cm);
		var dims = getDimensions(cm);

		// Compute a suitable new viewport (from & to)
		var end = doc.first + doc.size;
		var from = Math.max(visible.from - cm.options.viewportMargin, doc.first);
		var to = Math.min(end, visible.to + cm.options.viewportMargin);
		if (display.viewFrom < from && from - display.viewFrom < 20) from = Math.max(doc.first, display.viewFrom);
		if (display.viewTo > to && display.viewTo - to < 20) to = Math.min(end, display.viewTo);
		if (sawCollapsedSpans) {
			from = visualLineNo(cm.doc, from);
			to = visualLineEndNo(cm.doc, to);
		}

		var different = from != display.viewFrom || to != display.viewTo ||
			display.lastSizeC != display.wrapper.clientHeight;
		adjustView(cm, from, to);

		display.viewOffset = heightAtLine(getLine(cm.doc, display.viewFrom));
		// Position the mover div to align with the current scroll position
		cm.display.mover.style.top = display.viewOffset + "px";

		var toUpdate = countDirtyView(cm);
		if (!different && toUpdate == 0 && !forced) return;

		// For big changes, we hide the enclosing element during the
		// update, since that speeds up the operations on most browsers.
		var focused = activeElt();
		if (toUpdate > 4) display.lineDiv.style.display = "none";
		patchDisplay(cm, display.updateLineNumbers, dims);
		if (toUpdate > 4) display.lineDiv.style.display = "";
		// There might have been a widget with a focused element that got
		// hidden or updated, if so re-focus it.
		if (focused && activeElt() != focused && focused.offsetHeight) focused.focus();

		// Prevent selection and cursors from interfering with the scroll
		// width.
		removeChildren(display.cursorDiv);
		removeChildren(display.selectionDiv);

		if (different) {
			display.lastSizeC = display.wrapper.clientHeight;
			startWorker(cm, 400);
		}

		updateHeightsInViewport(cm);

		return true;
	}

	function adjustContentWidth(cm) {
		var display = cm.display;
		var width = measureChar(cm, display.maxLine, display.maxLine.text.length).left;
		display.maxLineChanged = false;
		var minWidth = Math.max(0, width + 3);
		var maxScrollLeft = Math.max(0, display.sizer.offsetLeft + minWidth + scrollerCutOff - display.scroller.clientWidth);
		display.sizer.style.minWidth = minWidth + "px";
		if (maxScrollLeft < cm.doc.scrollLeft)
			setScrollLeft(cm, Math.min(display.scroller.scrollLeft, maxScrollLeft), true);
	}

	function setDocumentHeight(cm, measure) {
		cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = measure.docHeight + "px";
		cm.display.gutters.style.height = Math.max(measure.docHeight, measure.clientHeight - scrollerCutOff) + "px";
	}

	function checkForWebkitWidthBug(cm, measure) {
		// Work around Webkit bug where it sometimes reserves space for a
		// non-existing phantom scrollbar in the scroller (Issue #2420)
		if (cm.display.sizer.offsetWidth + cm.display.gutters.offsetWidth < cm.display.scroller.clientWidth - 1) {
			cm.display.sizer.style.minHeight = cm.display.heightForcer.style.top = "0px";
			cm.display.gutters.style.height = measure.docHeight + "px";
		}
	}

	// Read the actual heights of the rendered lines, and update their
	// stored heights to match.
	function updateHeightsInViewport(cm) {
		var display = cm.display;
		var prevBottom = display.lineDiv.offsetTop;
		for (var i = 0; i < display.view.length; i++) {
			var cur = display.view[i], height;
			if (cur.hidden) continue;
			if (ie && ie_version < 8) {
				var bot = cur.node.offsetTop + cur.node.offsetHeight;
				height = bot - prevBottom;
				prevBottom = bot;
			} else {
				var box = cur.node.getBoundingClientRect();
				height = box.bottom - box.top;
			}
			var diff = cur.line.height - height;
			if (height < 2) height = textHeight(display);
			if (diff > .001 || diff < -.001) {
				updateLineHeight(cur.line, height);
				updateWidgetHeight(cur.line);
				if (cur.rest) for (var j = 0; j < cur.rest.length; j++)
					updateWidgetHeight(cur.rest[j]);
			}
		}
	}

	// Read and store the height of line widgets associated with the
	// given line.
	function updateWidgetHeight(line) {
		if (line.widgets) for (var i = 0; i < line.widgets.length; ++i)
			line.widgets[i].height = line.widgets[i].node.offsetHeight;
	}

	// Do a bulk-read of the DOM positions and sizes needed to draw the
	// view, so that we don't interleave reading and writing to the DOM.
	function getDimensions(cm) {
		var d = cm.display, left = {}, width = {};
		for (var n = d.gutters.firstChild, i = 0; n; n = n.nextSibling, ++i) {
			left[cm.options.gutters[i]] = n.offsetLeft;
			width[cm.options.gutters[i]] = n.offsetWidth;
		}
		return {fixedPos: compensateForHScroll(d),
			gutterTotalWidth: d.gutters.offsetWidth,
			gutterLeft: left,
			gutterWidth: width,
			wrapperWidth: d.wrapper.clientWidth};
	}

	// Sync the actual display DOM structure with display.view, removing
	// nodes for lines that are no longer in view, and creating the ones
	// that are not there yet, and updating the ones that are out of
	// date.
	function patchDisplay(cm, updateNumbersFrom, dims) {
		var display = cm.display, lineNumbers = cm.options.lineNumbers;
		var container = display.lineDiv, cur = container.firstChild;

		function rm(node) {
			var next = node.nextSibling;
			// Works around a throw-scroll bug in OS X Webkit
			if (webkit && mac && cm.display.currentWheelTarget == node)
				node.style.display = "none";
			else
				node.parentNode.removeChild(node);
			return next;
		}

		var view = display.view, lineN = display.viewFrom;
		// Loop over the elements in the view, syncing cur (the DOM nodes
		// in display.lineDiv) with the view as we go.
		for (var i = 0; i < view.length; i++) {
			var lineView = view[i];
			if (lineView.hidden) {
			} else if (!lineView.node) { // Not drawn yet
				var node = buildLineElement(cm, lineView, lineN, dims);
				container.insertBefore(node, cur);
			} else { // Already drawn
				while (cur != lineView.node) cur = rm(cur);
				var updateNumber = lineNumbers && updateNumbersFrom != null &&
					updateNumbersFrom <= lineN && lineView.lineNumber;
				if (lineView.changes) {
					if (indexOf(lineView.changes, "gutter") > -1) updateNumber = false;
					updateLineForChanges(cm, lineView, lineN, dims);
				}
				if (updateNumber) {
					removeChildren(lineView.lineNumber);
					lineView.lineNumber.appendChild(document.createTextNode(lineNumberFor(cm.options, lineN)));
				}
				cur = lineView.node.nextSibling;
			}
			lineN += lineView.size;
		}
		while (cur) cur = rm(cur);
	}

	// When an aspect of a line changes, a string is added to
	// lineView.changes. This updates the relevant part of the line's
	// DOM structure.
	function updateLineForChanges(cm, lineView, lineN, dims) {
		for (var j = 0; j < lineView.changes.length; j++) {
			var type = lineView.changes[j];
			if (type == "text") updateLineText(cm, lineView);
			else if (type == "gutter") updateLineGutter(cm, lineView, lineN, dims);
			else if (type == "class") updateLineClasses(lineView);
			else if (type == "widget") updateLineWidgets(lineView, dims);
		}
		lineView.changes = null;
	}

	// Lines with gutter elements, widgets or a background class need to
	// be wrapped, and have the extra elements added to the wrapper div
	function ensureLineWrapped(lineView) {
		if (lineView.node == lineView.text) {
			lineView.node = elt("div", null, null, "position: relative");
			if (lineView.text.parentNode)
				lineView.text.parentNode.replaceChild(lineView.node, lineView.text);
			lineView.node.appendChild(lineView.text);
			if (ie && ie_version < 8) lineView.node.style.zIndex = 2;
		}
		return lineView.node;
	}

	function updateLineBackground(lineView) {
		var cls = lineView.bgClass ? lineView.bgClass + " " + (lineView.line.bgClass || "") : lineView.line.bgClass;
		if (cls) cls += " CodeMirror-linebackground";
		if (lineView.background) {
			if (cls) lineView.background.className = cls;
			else { lineView.background.parentNode.removeChild(lineView.background); lineView.background = null; }
		} else if (cls) {
			var wrap = ensureLineWrapped(lineView);
			lineView.background = wrap.insertBefore(elt("div", null, cls), wrap.firstChild);
		}
	}

	// Wrapper around buildLineContent which will reuse the structure
	// in display.externalMeasured when possible.
	function getLineContent(cm, lineView) {
		var ext = cm.display.externalMeasured;
		if (ext && ext.line == lineView.line) {
			cm.display.externalMeasured = null;
			lineView.measure = ext.measure;
			return ext.built;
		}
		return buildLineContent(cm, lineView);
	}

	// Redraw the line's text. Interacts with the background and text
	// classes because the mode may output tokens that influence these
	// classes.
	function updateLineText(cm, lineView) {
		var cls = lineView.text.className;
		var built = getLineContent(cm, lineView);
		if (lineView.text == lineView.node) lineView.node = built.pre;
		lineView.text.parentNode.replaceChild(built.pre, lineView.text);
		lineView.text = built.pre;
		if (built.bgClass != lineView.bgClass || built.textClass != lineView.textClass) {
			lineView.bgClass = built.bgClass;
			lineView.textClass = built.textClass;
			updateLineClasses(lineView);
		} else if (cls) {
			lineView.text.className = cls;
		}
	}

	function updateLineClasses(lineView) {
		updateLineBackground(lineView);
		if (lineView.line.wrapClass)
			ensureLineWrapped(lineView).className = lineView.line.wrapClass;
		else if (lineView.node != lineView.text)
			lineView.node.className = "";
		var textClass = lineView.textClass ? lineView.textClass + " " + (lineView.line.textClass || "") : lineView.line.textClass;
		lineView.text.className = textClass || "";
	}

	function updateLineGutter(cm, lineView, lineN, dims) {
		if (lineView.gutter) {
			lineView.node.removeChild(lineView.gutter);
			lineView.gutter = null;
		}
		var markers = lineView.line.gutterMarkers;
		if (cm.options.lineNumbers || markers) {
			var wrap = ensureLineWrapped(lineView);
			var gutterWrap = lineView.gutter =
				wrap.insertBefore(elt("div", null, "CodeMirror-gutter-wrapper", "position: absolute; left: " +
						(cm.options.fixedGutter ? dims.fixedPos : -dims.gutterTotalWidth) + "px"),
					lineView.text);
			if (cm.options.lineNumbers && (!markers || !markers["CodeMirror-linenumbers"]))
				lineView.lineNumber = gutterWrap.appendChild(
					elt("div", lineNumberFor(cm.options, lineN),
						"CodeMirror-linenumber CodeMirror-gutter-elt",
						"left: " + dims.gutterLeft["CodeMirror-linenumbers"] + "px; width: "
						+ cm.display.lineNumInnerWidth + "px"));
			if (markers) for (var k = 0; k < cm.options.gutters.length; ++k) {
				var id = cm.options.gutters[k], found = markers.hasOwnProperty(id) && markers[id];
				if (found)
					gutterWrap.appendChild(elt("div", [found], "CodeMirror-gutter-elt", "left: " +
						dims.gutterLeft[id] + "px; width: " + dims.gutterWidth[id] + "px"));
			}
		}
	}

	function updateLineWidgets(lineView, dims) {
		if (lineView.alignable) lineView.alignable = null;
		for (var node = lineView.node.firstChild, next; node; node = next) {
			var next = node.nextSibling;
			if (node.className == "CodeMirror-linewidget")
				lineView.node.removeChild(node);
		}
		insertLineWidgets(lineView, dims);
	}

	// Build a line's DOM representation from scratch
	function buildLineElement(cm, lineView, lineN, dims) {
		var built = getLineContent(cm, lineView);
		lineView.text = lineView.node = built.pre;
		if (built.bgClass) lineView.bgClass = built.bgClass;
		if (built.textClass) lineView.textClass = built.textClass;

		updateLineClasses(lineView);
		updateLineGutter(cm, lineView, lineN, dims);
		insertLineWidgets(lineView, dims);
		return lineView.node;
	}

	// A lineView may contain multiple logical lines (when merged by
	// collapsed spans). The widgets for all of them need to be drawn.
	function insertLineWidgets(lineView, dims) {
		insertLineWidgetsFor(lineView.line, lineView, dims, true);
		if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
			insertLineWidgetsFor(lineView.rest[i], lineView, dims, false);
	}

	function insertLineWidgetsFor(line, lineView, dims, allowAbove) {
		if (!line.widgets) return;
		var wrap = ensureLineWrapped(lineView);
		for (var i = 0, ws = line.widgets; i < ws.length; ++i) {
			var widget = ws[i], node = elt("div", [widget.node], "CodeMirror-linewidget");
			if (!widget.handleMouseEvents) node.ignoreEvents = true;
			positionLineWidget(widget, node, lineView, dims);
			if (allowAbove && widget.above)
				wrap.insertBefore(node, lineView.gutter || lineView.text);
			else
				wrap.appendChild(node);
			signalLater(widget, "redraw");
		}
	}

	function positionLineWidget(widget, node, lineView, dims) {
		if (widget.noHScroll) {
			(lineView.alignable || (lineView.alignable = [])).push(node);
			var width = dims.wrapperWidth;
			node.style.left = dims.fixedPos + "px";
			if (!widget.coverGutter) {
				width -= dims.gutterTotalWidth;
				node.style.paddingLeft = dims.gutterTotalWidth + "px";
			}
			node.style.width = width + "px";
		}
		if (widget.coverGutter) {
			node.style.zIndex = 5;
			node.style.position = "relative";
			if (!widget.noHScroll) node.style.marginLeft = -dims.gutterTotalWidth + "px";
		}
	}

	// POSITION OBJECT

	// A Pos instance represents a position within the text.
	var Pos = CodeMirror.Pos = function(line, ch) {
		if (!(this instanceof Pos)) return new Pos(line, ch);
		this.line = line; this.ch = ch;
	};

	// Compare two positions, return 0 if they are the same, a negative
	// number when a is less, and a positive number otherwise.
	var cmp = CodeMirror.cmpPos = function(a, b) { return a.line - b.line || a.ch - b.ch; };

	function copyPos(x) {return Pos(x.line, x.ch);}
	function maxPos(a, b) { return cmp(a, b) < 0 ? b : a; }
	function minPos(a, b) { return cmp(a, b) < 0 ? a : b; }

	// SELECTION / CURSOR

	// Selection objects are immutable. A new one is created every time
	// the selection changes. A selection is one or more non-overlapping
	// (and non-touching) ranges, sorted, and an integer that indicates
	// which one is the primary selection (the one that's scrolled into
	// view, that getCursor returns, etc).
	function Selection(ranges, primIndex) {
		this.ranges = ranges;
		this.primIndex = primIndex;
	}

	Selection.prototype = {
		primary: function() { return this.ranges[this.primIndex]; },
		equals: function(other) {
			if (other == this) return true;
			if (other.primIndex != this.primIndex || other.ranges.length != this.ranges.length) return false;
			for (var i = 0; i < this.ranges.length; i++) {
				var here = this.ranges[i], there = other.ranges[i];
				if (cmp(here.anchor, there.anchor) != 0 || cmp(here.head, there.head) != 0) return false;
			}
			return true;
		},
		deepCopy: function() {
			for (var out = [], i = 0; i < this.ranges.length; i++)
				out[i] = new Range(copyPos(this.ranges[i].anchor), copyPos(this.ranges[i].head));
			return new Selection(out, this.primIndex);
		},
		somethingSelected: function() {
			for (var i = 0; i < this.ranges.length; i++)
				if (!this.ranges[i].empty()) return true;
			return false;
		},
		contains: function(pos, end) {
			if (!end) end = pos;
			for (var i = 0; i < this.ranges.length; i++) {
				var range = this.ranges[i];
				if (cmp(end, range.from()) >= 0 && cmp(pos, range.to()) <= 0)
					return i;
			}
			return -1;
		}
	};

	function Range(anchor, head) {
		this.anchor = anchor; this.head = head;
	}

	Range.prototype = {
		from: function() { return minPos(this.anchor, this.head); },
		to: function() { return maxPos(this.anchor, this.head); },
		empty: function() {
			return this.head.line == this.anchor.line && this.head.ch == this.anchor.ch;
		}
	};

	// Take an unsorted, potentially overlapping set of ranges, and
	// build a selection out of it. 'Consumes' ranges array (modifying
	// it).
	function normalizeSelection(ranges, primIndex) {
		var prim = ranges[primIndex];
		ranges.sort(function(a, b) { return cmp(a.from(), b.from()); });
		primIndex = indexOf(ranges, prim);
		for (var i = 1; i < ranges.length; i++) {
			var cur = ranges[i], prev = ranges[i - 1];
			if (cmp(prev.to(), cur.from()) >= 0) {
				var from = minPos(prev.from(), cur.from()), to = maxPos(prev.to(), cur.to());
				var inv = prev.empty() ? cur.from() == cur.head : prev.from() == prev.head;
				if (i <= primIndex) --primIndex;
				ranges.splice(--i, 2, new Range(inv ? to : from, inv ? from : to));
			}
		}
		return new Selection(ranges, primIndex);
	}

	function simpleSelection(anchor, head) {
		return new Selection([new Range(anchor, head || anchor)], 0);
	}

	// Most of the external API clips given positions to make sure they
	// actually exist within the document.
	function clipLine(doc, n) {return Math.max(doc.first, Math.min(n, doc.first + doc.size - 1));}
	function clipPos(doc, pos) {
		if (pos.line < doc.first) return Pos(doc.first, 0);
		var last = doc.first + doc.size - 1;
		if (pos.line > last) return Pos(last, getLine(doc, last).text.length);
		return clipToLen(pos, getLine(doc, pos.line).text.length);
	}
	function clipToLen(pos, linelen) {
		var ch = pos.ch;
		if (ch == null || ch > linelen) return Pos(pos.line, linelen);
		else if (ch < 0) return Pos(pos.line, 0);
		else return pos;
	}
	function isLine(doc, l) {return l >= doc.first && l < doc.first + doc.size;}
	function clipPosArray(doc, array) {
		for (var out = [], i = 0; i < array.length; i++) out[i] = clipPos(doc, array[i]);
		return out;
	}

	// SELECTION UPDATES

	// The 'scroll' parameter given to many of these indicated whether
	// the new cursor position should be scrolled into view after
	// modifying the selection.

	// If shift is held or the extend flag is set, extends a range to
	// include a given position (and optionally a second position).
	// Otherwise, simply returns the range between the given positions.
	// Used for cursor motion and such.
	function extendRange(doc, range, head, other) {
		if (doc.cm && doc.cm.display.shift || doc.extend) {
			var anchor = range.anchor;
			if (other) {
				var posBefore = cmp(head, anchor) < 0;
				if (posBefore != (cmp(other, anchor) < 0)) {
					anchor = head;
					head = other;
				} else if (posBefore != (cmp(head, other) < 0)) {
					head = other;
				}
			}
			return new Range(anchor, head);
		} else {
			return new Range(other || head, head);
		}
	}

	// Extend the primary selection range, discard the rest.
	function extendSelection(doc, head, other, options) {
		setSelection(doc, new Selection([extendRange(doc, doc.sel.primary(), head, other)], 0), options);
	}

	// Extend all selections (pos is an array of selections with length
	// equal the number of selections)
	function extendSelections(doc, heads, options) {
		for (var out = [], i = 0; i < doc.sel.ranges.length; i++)
			out[i] = extendRange(doc, doc.sel.ranges[i], heads[i], null);
		var newSel = normalizeSelection(out, doc.sel.primIndex);
		setSelection(doc, newSel, options);
	}

	// Updates a single range in the selection.
	function replaceOneSelection(doc, i, range, options) {
		var ranges = doc.sel.ranges.slice(0);
		ranges[i] = range;
		setSelection(doc, normalizeSelection(ranges, doc.sel.primIndex), options);
	}

	// Reset the selection to a single range.
	function setSimpleSelection(doc, anchor, head, options) {
		setSelection(doc, simpleSelection(anchor, head), options);
	}

	// Give beforeSelectionChange handlers a change to influence a
	// selection update.
	function filterSelectionChange(doc, sel) {
		var obj = {
			ranges: sel.ranges,
			update: function(ranges) {
				this.ranges = [];
				for (var i = 0; i < ranges.length; i++)
					this.ranges[i] = new Range(clipPos(doc, ranges[i].anchor),
						clipPos(doc, ranges[i].head));
			}
		};
		signal(doc, "beforeSelectionChange", doc, obj);
		if (doc.cm) signal(doc.cm, "beforeSelectionChange", doc.cm, obj);
		if (obj.ranges != sel.ranges) return normalizeSelection(obj.ranges, obj.ranges.length - 1);
		else return sel;
	}

	function setSelectionReplaceHistory(doc, sel, options) {
		var done = doc.history.done, last = lst(done);
		if (last && last.ranges) {
			done[done.length - 1] = sel;
			setSelectionNoUndo(doc, sel, options);
		} else {
			setSelection(doc, sel, options);
		}
	}

	// Set a new selection.
	function setSelection(doc, sel, options) {
		setSelectionNoUndo(doc, sel, options);
		addSelectionToHistory(doc, doc.sel, doc.cm ? doc.cm.curOp.id : NaN, options);
	}

	function setSelectionNoUndo(doc, sel, options) {
		if (hasHandler(doc, "beforeSelectionChange") || doc.cm && hasHandler(doc.cm, "beforeSelectionChange"))
			sel = filterSelectionChange(doc, sel);

		var bias = options && options.bias ||
			(cmp(sel.primary().head, doc.sel.primary().head) < 0 ? -1 : 1);
		setSelectionInner(doc, skipAtomicInSelection(doc, sel, bias, true));

		if (!(options && options.scroll === false) && doc.cm)
			ensureCursorVisible(doc.cm);
	}

	function setSelectionInner(doc, sel) {
		if (sel.equals(doc.sel)) return;

		doc.sel = sel;

		if (doc.cm) {
			doc.cm.curOp.updateInput = doc.cm.curOp.selectionChanged = true;
			signalCursorActivity(doc.cm);
		}
		signalLater(doc, "cursorActivity", doc);
	}

	// Verify that the selection does not partially select any atomic
	// marked ranges.
	function reCheckSelection(doc) {
		setSelectionInner(doc, skipAtomicInSelection(doc, doc.sel, null, false), sel_dontScroll);
	}

	// Return a selection that does not partially select any atomic
	// ranges.
	function skipAtomicInSelection(doc, sel, bias, mayClear) {
		var out;
		for (var i = 0; i < sel.ranges.length; i++) {
			var range = sel.ranges[i];
			var newAnchor = skipAtomic(doc, range.anchor, bias, mayClear);
			var newHead = skipAtomic(doc, range.head, bias, mayClear);
			if (out || newAnchor != range.anchor || newHead != range.head) {
				if (!out) out = sel.ranges.slice(0, i);
				out[i] = new Range(newAnchor, newHead);
			}
		}
		return out ? normalizeSelection(out, sel.primIndex) : sel;
	}

	// Ensure a given position is not inside an atomic range.
	function skipAtomic(doc, pos, bias, mayClear) {
		var flipped = false, curPos = pos;
		var dir = bias || 1;
		doc.cantEdit = false;
		search: for (;;) {
			var line = getLine(doc, curPos.line);
			if (line.markedSpans) {
				for (var i = 0; i < line.markedSpans.length; ++i) {
					var sp = line.markedSpans[i], m = sp.marker;
					if ((sp.from == null || (m.inclusiveLeft ? sp.from <= curPos.ch : sp.from < curPos.ch)) &&
						(sp.to == null || (m.inclusiveRight ? sp.to >= curPos.ch : sp.to > curPos.ch))) {
						if (mayClear) {
							signal(m, "beforeCursorEnter");
							if (m.explicitlyCleared) {
								if (!line.markedSpans) break;
								else {--i; continue;}
							}
						}
						if (!m.atomic) continue;
						var newPos = m.find(dir < 0 ? -1 : 1);
						if (cmp(newPos, curPos) == 0) {
							newPos.ch += dir;
							if (newPos.ch < 0) {
								if (newPos.line > doc.first) newPos = clipPos(doc, Pos(newPos.line - 1));
								else newPos = null;
							} else if (newPos.ch > line.text.length) {
								if (newPos.line < doc.first + doc.size - 1) newPos = Pos(newPos.line + 1, 0);
								else newPos = null;
							}
							if (!newPos) {
								if (flipped) {
									// Driven in a corner -- no valid cursor position found at all
									// -- try again *with* clearing, if we didn't already
									if (!mayClear) return skipAtomic(doc, pos, bias, true);
									// Otherwise, turn off editing until further notice, and return the start of the doc
									doc.cantEdit = true;
									return Pos(doc.first, 0);
								}
								flipped = true; newPos = pos; dir = -dir;
							}
						}
						curPos = newPos;
						continue search;
					}
				}
			}
			return curPos;
		}
	}

	// SELECTION DRAWING

	// Redraw the selection and/or cursor
	function updateSelection(cm) {
		var display = cm.display, doc = cm.doc;
		var curFragment = document.createDocumentFragment();
		var selFragment = document.createDocumentFragment();

		for (var i = 0; i < doc.sel.ranges.length; i++) {
			var range = doc.sel.ranges[i];
			var collapsed = range.empty();
			if (collapsed || cm.options.showCursorWhenSelecting)
				drawSelectionCursor(cm, range, curFragment);
			if (!collapsed)
				drawSelectionRange(cm, range, selFragment);
		}

		// Move the hidden textarea near the cursor to prevent scrolling artifacts
		if (cm.options.moveInputWithCursor) {
			var headPos = cursorCoords(cm, doc.sel.primary().head, "div");
			var wrapOff = display.wrapper.getBoundingClientRect(), lineOff = display.lineDiv.getBoundingClientRect();
			var top = Math.max(0, Math.min(display.wrapper.clientHeight - 10,
				headPos.top + lineOff.top - wrapOff.top));
			var left = Math.max(0, Math.min(display.wrapper.clientWidth - 10,
				headPos.left + lineOff.left - wrapOff.left));
			display.inputDiv.style.top = top + "px";
			display.inputDiv.style.left = left + "px";
		}

		removeChildrenAndAdd(display.cursorDiv, curFragment);
		removeChildrenAndAdd(display.selectionDiv, selFragment);
	}

	// Draws a cursor for the given range
	function drawSelectionCursor(cm, range, output) {
		var pos = cursorCoords(cm, range.head, "div", null, null, !cm.options.singleCursorHeightPerLine);

		var cursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor"));
		cursor.style.left = pos.left + "px";
		cursor.style.top = pos.top + "px";
		cursor.style.height = Math.max(0, pos.bottom - pos.top) * cm.options.cursorHeight + "px";

		if (pos.other) {
			// Secondary cursor, shown when on a 'jump' in bi-directional text
			var otherCursor = output.appendChild(elt("div", "\u00a0", "CodeMirror-cursor CodeMirror-secondarycursor"));
			otherCursor.style.display = "";
			otherCursor.style.left = pos.other.left + "px";
			otherCursor.style.top = pos.other.top + "px";
			otherCursor.style.height = (pos.other.bottom - pos.other.top) * .85 + "px";
		}
	}

	// Draws the given range as a highlighted selection
	function drawSelectionRange(cm, range, output) {
		var display = cm.display, doc = cm.doc;
		var fragment = document.createDocumentFragment();
		var padding = paddingH(cm.display), leftSide = padding.left, rightSide = display.lineSpace.offsetWidth - padding.right;

		function add(left, top, width, bottom) {
			if (top < 0) top = 0;
			top = Math.round(top);
			bottom = Math.round(bottom);
			fragment.appendChild(elt("div", null, "CodeMirror-selected", "position: absolute; left: " + left +
				"px; top: " + top + "px; width: " + (width == null ? rightSide - left : width) +
				"px; height: " + (bottom - top) + "px"));
		}

		function drawForLine(line, fromArg, toArg) {
			var lineObj = getLine(doc, line);
			var lineLen = lineObj.text.length;
			var start, end;
			function coords(ch, bias) {
				return charCoords(cm, Pos(line, ch), "div", lineObj, bias);
			}

			iterateBidiSections(getOrder(lineObj), fromArg || 0, toArg == null ? lineLen : toArg, function(from, to, dir) {
				var leftPos = coords(from, "left"), rightPos, left, right;
				if (from == to) {
					rightPos = leftPos;
					left = right = leftPos.left;
				} else {
					rightPos = coords(to - 1, "right");
					if (dir == "rtl") { var tmp = leftPos; leftPos = rightPos; rightPos = tmp; }
					left = leftPos.left;
					right = rightPos.right;
				}
				if (fromArg == null && from == 0) left = leftSide;
				if (rightPos.top - leftPos.top > 3) { // Different lines, draw top part
					add(left, leftPos.top, null, leftPos.bottom);
					left = leftSide;
					if (leftPos.bottom < rightPos.top) add(left, leftPos.bottom, null, rightPos.top);
				}
				if (toArg == null && to == lineLen) right = rightSide;
				if (!start || leftPos.top < start.top || leftPos.top == start.top && leftPos.left < start.left)
					start = leftPos;
				if (!end || rightPos.bottom > end.bottom || rightPos.bottom == end.bottom && rightPos.right > end.right)
					end = rightPos;
				if (left < leftSide + 1) left = leftSide;
				add(left, rightPos.top, right - left, rightPos.bottom);
			});
			return {start: start, end: end};
		}

		var sFrom = range.from(), sTo = range.to();
		if (sFrom.line == sTo.line) {
			drawForLine(sFrom.line, sFrom.ch, sTo.ch);
		} else {
			var fromLine = getLine(doc, sFrom.line), toLine = getLine(doc, sTo.line);
			var singleVLine = visualLine(fromLine) == visualLine(toLine);
			var leftEnd = drawForLine(sFrom.line, sFrom.ch, singleVLine ? fromLine.text.length + 1 : null).end;
			var rightStart = drawForLine(sTo.line, singleVLine ? 0 : null, sTo.ch).start;
			if (singleVLine) {
				if (leftEnd.top < rightStart.top - 2) {
					add(leftEnd.right, leftEnd.top, null, leftEnd.bottom);
					add(leftSide, rightStart.top, rightStart.left, rightStart.bottom);
				} else {
					add(leftEnd.right, leftEnd.top, rightStart.left - leftEnd.right, leftEnd.bottom);
				}
			}
			if (leftEnd.bottom < rightStart.top)
				add(leftSide, leftEnd.bottom, null, rightStart.top);
		}

		output.appendChild(fragment);
	}

	// Cursor-blinking
	function restartBlink(cm) {
		if (!cm.state.focused) return;
		var display = cm.display;
		clearInterval(display.blinker);
		var on = true;
		display.cursorDiv.style.visibility = "";
		if (cm.options.cursorBlinkRate > 0)
			display.blinker = setInterval(function() {
				display.cursorDiv.style.visibility = (on = !on) ? "" : "hidden";
			}, cm.options.cursorBlinkRate);
		else if (cm.options.cursorBlinkRate < 0)
			display.cursorDiv.style.visibility = "hidden";
	}

	// HIGHLIGHT WORKER

	function startWorker(cm, time) {
		if (cm.doc.mode.startState && cm.doc.frontier < cm.display.viewTo)
			cm.state.highlight.set(time, bind(highlightWorker, cm));
	}

	function highlightWorker(cm) {
		var doc = cm.doc;
		if (doc.frontier < doc.first) doc.frontier = doc.first;
		if (doc.frontier >= cm.display.viewTo) return;
		var end = +new Date + cm.options.workTime;
		var state = copyState(doc.mode, getStateBefore(cm, doc.frontier));

		runInOp(cm, function() {
			doc.iter(doc.frontier, Math.min(doc.first + doc.size, cm.display.viewTo + 500), function(line) {
				if (doc.frontier >= cm.display.viewFrom) { // Visible
					var oldStyles = line.styles;
					var highlighted = highlightLine(cm, line, state, true);
					line.styles = highlighted.styles;
					var oldCls = line.styleClasses, newCls = highlighted.classes;
					if (newCls) line.styleClasses = newCls;
					else if (oldCls) line.styleClasses = null;
					var ischange = !oldStyles || oldStyles.length != line.styles.length ||
						oldCls != newCls && (!oldCls || !newCls || oldCls.bgClass != newCls.bgClass || oldCls.textClass != newCls.textClass);
					for (var i = 0; !ischange && i < oldStyles.length; ++i) ischange = oldStyles[i] != line.styles[i];
					if (ischange) regLineChange(cm, doc.frontier, "text");
					line.stateAfter = copyState(doc.mode, state);
				} else {
					processLine(cm, line.text, state);
					line.stateAfter = doc.frontier % 5 == 0 ? copyState(doc.mode, state) : null;
				}
				++doc.frontier;
				if (+new Date > end) {
					startWorker(cm, cm.options.workDelay);
					return true;
				}
			});
		});
	}

	// Finds the line to start with when starting a parse. Tries to
	// find a line with a stateAfter, so that it can start with a
	// valid state. If that fails, it returns the line with the
	// smallest indentation, which tends to need the least context to
	// parse correctly.
	function findStartLine(cm, n, precise) {
		var minindent, minline, doc = cm.doc;
		var lim = precise ? -1 : n - (cm.doc.mode.innerMode ? 1000 : 100);
		for (var search = n; search > lim; --search) {
			if (search <= doc.first) return doc.first;
			var line = getLine(doc, search - 1);
			if (line.stateAfter && (!precise || search <= doc.frontier)) return search;
			var indented = countColumn(line.text, null, cm.options.tabSize);
			if (minline == null || minindent > indented) {
				minline = search - 1;
				minindent = indented;
			}
		}
		return minline;
	}

	function getStateBefore(cm, n, precise) {
		var doc = cm.doc, display = cm.display;
		if (!doc.mode.startState) return true;
		var pos = findStartLine(cm, n, precise), state = pos > doc.first && getLine(doc, pos-1).stateAfter;
		if (!state) state = startState(doc.mode);
		else state = copyState(doc.mode, state);
		doc.iter(pos, n, function(line) {
			processLine(cm, line.text, state);
			var save = pos == n - 1 || pos % 5 == 0 || pos >= display.viewFrom && pos < display.viewTo;
			line.stateAfter = save ? copyState(doc.mode, state) : null;
			++pos;
		});
		if (precise) doc.frontier = pos;
		return state;
	}

	// POSITION MEASUREMENT

	function paddingTop(display) {return display.lineSpace.offsetTop;}
	function paddingVert(display) {return display.mover.offsetHeight - display.lineSpace.offsetHeight;}
	function paddingH(display) {
		if (display.cachedPaddingH) return display.cachedPaddingH;
		var e = removeChildrenAndAdd(display.measure, elt("pre", "x"));
		var style = window.getComputedStyle ? window.getComputedStyle(e) : e.currentStyle;
		var data = {left: parseInt(style.paddingLeft), right: parseInt(style.paddingRight)};
		if (!isNaN(data.left) && !isNaN(data.right)) display.cachedPaddingH = data;
		return data;
	}

	// Ensure the lineView.wrapping.heights array is populated. This is
	// an array of bottom offsets for the lines that make up a drawn
	// line. When lineWrapping is on, there might be more than one
	// height.
	function ensureLineHeights(cm, lineView, rect) {
		var wrapping = cm.options.lineWrapping;
		var curWidth = wrapping && cm.display.scroller.clientWidth;
		if (!lineView.measure.heights || wrapping && lineView.measure.width != curWidth) {
			var heights = lineView.measure.heights = [];
			if (wrapping) {
				lineView.measure.width = curWidth;
				var rects = lineView.text.firstChild.getClientRects();
				for (var i = 0; i < rects.length - 1; i++) {
					var cur = rects[i], next = rects[i + 1];
					if (Math.abs(cur.bottom - next.bottom) > 2)
						heights.push((cur.bottom + next.top) / 2 - rect.top);
				}
			}
			heights.push(rect.bottom - rect.top);
		}
	}

	// Find a line map (mapping character offsets to text nodes) and a
	// measurement cache for the given line number. (A line view might
	// contain multiple lines when collapsed ranges are present.)
	function mapFromLineView(lineView, line, lineN) {
		if (lineView.line == line)
			return {map: lineView.measure.map, cache: lineView.measure.cache};
		for (var i = 0; i < lineView.rest.length; i++)
			if (lineView.rest[i] == line)
				return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i]};
		for (var i = 0; i < lineView.rest.length; i++)
			if (lineNo(lineView.rest[i]) > lineN)
				return {map: lineView.measure.maps[i], cache: lineView.measure.caches[i], before: true};
	}

	// Render a line into the hidden node display.externalMeasured. Used
	// when measurement is needed for a line that's not in the viewport.
	function updateExternalMeasurement(cm, line) {
		line = visualLine(line);
		var lineN = lineNo(line);
		var view = cm.display.externalMeasured = new LineView(cm.doc, line, lineN);
		view.lineN = lineN;
		var built = view.built = buildLineContent(cm, view);
		view.text = built.pre;
		removeChildrenAndAdd(cm.display.lineMeasure, built.pre);
		return view;
	}

	// Get a {top, bottom, left, right} box (in line-local coordinates)
	// for a given character.
	function measureChar(cm, line, ch, bias) {
		return measureCharPrepared(cm, prepareMeasureForLine(cm, line), ch, bias);
	}

	// Find a line view that corresponds to the given line number.
	function findViewForLine(cm, lineN) {
		if (lineN >= cm.display.viewFrom && lineN < cm.display.viewTo)
			return cm.display.view[findViewIndex(cm, lineN)];
		var ext = cm.display.externalMeasured;
		if (ext && lineN >= ext.lineN && lineN < ext.lineN + ext.size)
			return ext;
	}

	// Measurement can be split in two steps, the set-up work that
	// applies to the whole line, and the measurement of the actual
	// character. Functions like coordsChar, that need to do a lot of
	// measurements in a row, can thus ensure that the set-up work is
	// only done once.
	function prepareMeasureForLine(cm, line) {
		var lineN = lineNo(line);
		var view = findViewForLine(cm, lineN);
		if (view && !view.text)
			view = null;
		else if (view && view.changes)
			updateLineForChanges(cm, view, lineN, getDimensions(cm));
		if (!view)
			view = updateExternalMeasurement(cm, line);

		var info = mapFromLineView(view, line, lineN);
		return {
			line: line, view: view, rect: null,
			map: info.map, cache: info.cache, before: info.before,
			hasHeights: false
		};
	}

	// Given a prepared measurement object, measures the position of an
	// actual character (or fetches it from the cache).
	function measureCharPrepared(cm, prepared, ch, bias, varHeight) {
		if (prepared.before) ch = -1;
		var key = ch + (bias || ""), found;
		if (prepared.cache.hasOwnProperty(key)) {
			found = prepared.cache[key];
		} else {
			if (!prepared.rect)
				prepared.rect = prepared.view.text.getBoundingClientRect();
			if (!prepared.hasHeights) {
				ensureLineHeights(cm, prepared.view, prepared.rect);
				prepared.hasHeights = true;
			}
			found = measureCharInner(cm, prepared, ch, bias);
			if (!found.bogus) prepared.cache[key] = found;
		}
		return {left: found.left, right: found.right,
			top: varHeight ? found.rtop : found.top,
			bottom: varHeight ? found.rbottom : found.bottom};
	}

	var nullRect = {left: 0, right: 0, top: 0, bottom: 0};

	function measureCharInner(cm, prepared, ch, bias) {
		var map = prepared.map;

		var node, start, end, collapse;
		// First, search the line map for the text node corresponding to,
		// or closest to, the target character.
		for (var i = 0; i < map.length; i += 3) {
			var mStart = map[i], mEnd = map[i + 1];
			if (ch < mStart) {
				start = 0; end = 1;
				collapse = "left";
			} else if (ch < mEnd) {
				start = ch - mStart;
				end = start + 1;
			} else if (i == map.length - 3 || ch == mEnd && map[i + 3] > ch) {
				end = mEnd - mStart;
				start = end - 1;
				if (ch >= mEnd) collapse = "right";
			}
			if (start != null) {
				node = map[i + 2];
				if (mStart == mEnd && bias == (node.insertLeft ? "left" : "right"))
					collapse = bias;
				if (bias == "left" && start == 0)
					while (i && map[i - 2] == map[i - 3] && map[i - 1].insertLeft) {
						node = map[(i -= 3) + 2];
						collapse = "left";
					}
				if (bias == "right" && start == mEnd - mStart)
					while (i < map.length - 3 && map[i + 3] == map[i + 4] && !map[i + 5].insertLeft) {
						node = map[(i += 3) + 2];
						collapse = "right";
					}
				break;
			}
		}

		var rect;
		if (node.nodeType == 3) { // If it is a text node, use a range to retrieve the coordinates.
			while (start && isExtendingChar(prepared.line.text.charAt(mStart + start))) --start;
			while (mStart + end < mEnd && isExtendingChar(prepared.line.text.charAt(mStart + end))) ++end;
			if (ie && ie_version < 9 && start == 0 && end == mEnd - mStart) {
				rect = node.parentNode.getBoundingClientRect();
			} else if (ie && cm.options.lineWrapping) {
				var rects = range(node, start, end).getClientRects();
				if (rects.length)
					rect = rects[bias == "right" ? rects.length - 1 : 0];
				else
					rect = nullRect;
			} else {
				rect = range(node, start, end).getBoundingClientRect() || nullRect;
			}
		} else { // If it is a widget, simply get the box for the whole widget.
			if (start > 0) collapse = bias = "right";
			var rects;
			if (cm.options.lineWrapping && (rects = node.getClientRects()).length > 1)
				rect = rects[bias == "right" ? rects.length - 1 : 0];
			else
				rect = node.getBoundingClientRect();
		}
		if (ie && ie_version < 9 && !start && (!rect || !rect.left && !rect.right)) {
			var rSpan = node.parentNode.getClientRects()[0];
			if (rSpan)
				rect = {left: rSpan.left, right: rSpan.left + charWidth(cm.display), top: rSpan.top, bottom: rSpan.bottom};
			else
				rect = nullRect;
		}

		var rtop = rect.top - prepared.rect.top, rbot = rect.bottom - prepared.rect.top;
		var mid = (rtop + rbot) / 2;
		var heights = prepared.view.measure.heights;
		for (var i = 0; i < heights.length - 1; i++)
			if (mid < heights[i]) break;
		var top = i ? heights[i - 1] : 0, bot = heights[i];
		var result = {left: (collapse == "right" ? rect.right : rect.left) - prepared.rect.left,
			right: (collapse == "left" ? rect.left : rect.right) - prepared.rect.left,
			top: top, bottom: bot};
		if (!rect.left && !rect.right) result.bogus = true;
		if (!cm.options.singleCursorHeightPerLine) { result.rtop = rtop; result.rbottom = rbot; }
		return result;
	}

	function clearLineMeasurementCacheFor(lineView) {
		if (lineView.measure) {
			lineView.measure.cache = {};
			lineView.measure.heights = null;
			if (lineView.rest) for (var i = 0; i < lineView.rest.length; i++)
				lineView.measure.caches[i] = {};
		}
	}

	function clearLineMeasurementCache(cm) {
		cm.display.externalMeasure = null;
		removeChildren(cm.display.lineMeasure);
		for (var i = 0; i < cm.display.view.length; i++)
			clearLineMeasurementCacheFor(cm.display.view[i]);
	}

	function clearCaches(cm) {
		clearLineMeasurementCache(cm);
		cm.display.cachedCharWidth = cm.display.cachedTextHeight = cm.display.cachedPaddingH = null;
		if (!cm.options.lineWrapping) cm.display.maxLineChanged = true;
		cm.display.lineNumChars = null;
	}

	function pageScrollX() { return window.pageXOffset || (document.documentElement || document.body).scrollLeft; }
	function pageScrollY() { return window.pageYOffset || (document.documentElement || document.body).scrollTop; }

	// Converts a {top, bottom, left, right} box from line-local
	// coordinates into another coordinate system. Context may be one of
	// "line", "div" (display.lineDiv), "local"/null (editor), or "page".
	function intoCoordSystem(cm, lineObj, rect, context) {
		if (lineObj.widgets) for (var i = 0; i < lineObj.widgets.length; ++i) if (lineObj.widgets[i].above) {
			var size = widgetHeight(lineObj.widgets[i]);
			rect.top += size; rect.bottom += size;
		}
		if (context == "line") return rect;
		if (!context) context = "local";
		var yOff = heightAtLine(lineObj);
		if (context == "local") yOff += paddingTop(cm.display);
		else yOff -= cm.display.viewOffset;
		if (context == "page" || context == "window") {
			var lOff = cm.display.lineSpace.getBoundingClientRect();
			yOff += lOff.top + (context == "window" ? 0 : pageScrollY());
			var xOff = lOff.left + (context == "window" ? 0 : pageScrollX());
			rect.left += xOff; rect.right += xOff;
		}
		rect.top += yOff; rect.bottom += yOff;
		return rect;
	}

	// Coverts a box from "div" coords to another coordinate system.
	// Context may be "window", "page", "div", or "local"/null.
	function fromCoordSystem(cm, coords, context) {
		if (context == "div") return coords;
		var left = coords.left, top = coords.top;
		// First move into "page" coordinate system
		if (context == "page") {
			left -= pageScrollX();
			top -= pageScrollY();
		} else if (context == "local" || !context) {
			var localBox = cm.display.sizer.getBoundingClientRect();
			left += localBox.left;
			top += localBox.top;
		}

		var lineSpaceBox = cm.display.lineSpace.getBoundingClientRect();
		return {left: left - lineSpaceBox.left, top: top - lineSpaceBox.top};
	}

	function charCoords(cm, pos, context, lineObj, bias) {
		if (!lineObj) lineObj = getLine(cm.doc, pos.line);
		return intoCoordSystem(cm, lineObj, measureChar(cm, lineObj, pos.ch, bias), context);
	}

	// Returns a box for a given cursor position, which may have an
	// 'other' property containing the position of the secondary cursor
	// on a bidi boundary.
	function cursorCoords(cm, pos, context, lineObj, preparedMeasure, varHeight) {
		lineObj = lineObj || getLine(cm.doc, pos.line);
		if (!preparedMeasure) preparedMeasure = prepareMeasureForLine(cm, lineObj);
		function get(ch, right) {
			var m = measureCharPrepared(cm, preparedMeasure, ch, right ? "right" : "left", varHeight);
			if (right) m.left = m.right; else m.right = m.left;
			return intoCoordSystem(cm, lineObj, m, context);
		}
		function getBidi(ch, partPos) {
			var part = order[partPos], right = part.level % 2;
			if (ch == bidiLeft(part) && partPos && part.level < order[partPos - 1].level) {
				part = order[--partPos];
				ch = bidiRight(part) - (part.level % 2 ? 0 : 1);
				right = true;
			} else if (ch == bidiRight(part) && partPos < order.length - 1 && part.level < order[partPos + 1].level) {
				part = order[++partPos];
				ch = bidiLeft(part) - part.level % 2;
				right = false;
			}
			if (right && ch == part.to && ch > part.from) return get(ch - 1);
			return get(ch, right);
		}
		var order = getOrder(lineObj), ch = pos.ch;
		if (!order) return get(ch);
		var partPos = getBidiPartAt(order, ch);
		var val = getBidi(ch, partPos);
		if (bidiOther != null) val.other = getBidi(ch, bidiOther);
		return val;
	}

	// Used to cheaply estimate the coordinates for a position. Used for
	// intermediate scroll updates.
	function estimateCoords(cm, pos) {
		var left = 0, pos = clipPos(cm.doc, pos);
		if (!cm.options.lineWrapping) left = charWidth(cm.display) * pos.ch;
		var lineObj = getLine(cm.doc, pos.line);
		var top = heightAtLine(lineObj) + paddingTop(cm.display);
		return {left: left, right: left, top: top, bottom: top + lineObj.height};
	}

	// Positions returned by coordsChar contain some extra information.
	// xRel is the relative x position of the input coordinates compared
	// to the found position (so xRel > 0 means the coordinates are to
	// the right of the character position, for example). When outside
	// is true, that means the coordinates lie outside the line's
	// vertical range.
	function PosWithInfo(line, ch, outside, xRel) {
		var pos = Pos(line, ch);
		pos.xRel = xRel;
		if (outside) pos.outside = true;
		return pos;
	}

	// Compute the character position closest to the given coordinates.
	// Input must be lineSpace-local ("div" coordinate system).
	function coordsChar(cm, x, y) {
		var doc = cm.doc;
		y += cm.display.viewOffset;
		if (y < 0) return PosWithInfo(doc.first, 0, true, -1);
		var lineN = lineAtHeight(doc, y), last = doc.first + doc.size - 1;
		if (lineN > last)
			return PosWithInfo(doc.first + doc.size - 1, getLine(doc, last).text.length, true, 1);
		if (x < 0) x = 0;

		var lineObj = getLine(doc, lineN);
		for (;;) {
			var found = coordsCharInner(cm, lineObj, lineN, x, y);
			var merged = collapsedSpanAtEnd(lineObj);
			var mergedPos = merged && merged.find(0, true);
			if (merged && (found.ch > mergedPos.from.ch || found.ch == mergedPos.from.ch && found.xRel > 0))
				lineN = lineNo(lineObj = mergedPos.to.line);
			else
				return found;
		}
	}

	function coordsCharInner(cm, lineObj, lineNo, x, y) {
		var innerOff = y - heightAtLine(lineObj);
		var wrongLine = false, adjust = 2 * cm.display.wrapper.clientWidth;
		var preparedMeasure = prepareMeasureForLine(cm, lineObj);

		function getX(ch) {
			var sp = cursorCoords(cm, Pos(lineNo, ch), "line", lineObj, preparedMeasure);
			wrongLine = true;
			if (innerOff > sp.bottom) return sp.left - adjust;
			else if (innerOff < sp.top) return sp.left + adjust;
			else wrongLine = false;
			return sp.left;
		}

		var bidi = getOrder(lineObj), dist = lineObj.text.length;
		var from = lineLeft(lineObj), to = lineRight(lineObj);
		var fromX = getX(from), fromOutside = wrongLine, toX = getX(to), toOutside = wrongLine;

		if (x > toX) return PosWithInfo(lineNo, to, toOutside, 1);
		// Do a binary search between these bounds.
		for (;;) {
			if (bidi ? to == from || to == moveVisually(lineObj, from, 1) : to - from <= 1) {
				var ch = x < fromX || x - fromX <= toX - x ? from : to;
				var xDiff = x - (ch == from ? fromX : toX);
				while (isExtendingChar(lineObj.text.charAt(ch))) ++ch;
				var pos = PosWithInfo(lineNo, ch, ch == from ? fromOutside : toOutside,
					xDiff < -1 ? -1 : xDiff > 1 ? 1 : 0);
				return pos;
			}
			var step = Math.ceil(dist / 2), middle = from + step;
			if (bidi) {
				middle = from;
				for (var i = 0; i < step; ++i) middle = moveVisually(lineObj, middle, 1);
			}
			var middleX = getX(middle);
			if (middleX > x) {to = middle; toX = middleX; if (toOutside = wrongLine) toX += 1000; dist = step;}
			else {from = middle; fromX = middleX; fromOutside = wrongLine; dist -= step;}
		}
	}

	var measureText;
	// Compute the default text height.
	function textHeight(display) {
		if (display.cachedTextHeight != null) return display.cachedTextHeight;
		if (measureText == null) {
			measureText = elt("pre");
			// Measure a bunch of lines, for browsers that compute
			// fractional heights.
			for (var i = 0; i < 49; ++i) {
				measureText.appendChild(document.createTextNode("x"));
				measureText.appendChild(elt("br"));
			}
			measureText.appendChild(document.createTextNode("x"));
		}
		removeChildrenAndAdd(display.measure, measureText);
		var height = measureText.offsetHeight / 50;
		if (height > 3) display.cachedTextHeight = height;
		removeChildren(display.measure);
		return height || 1;
	}

	// Compute the default character width.
	function charWidth(display) {
		if (display.cachedCharWidth != null) return display.cachedCharWidth;
		var anchor = elt("span", "xxxxxxxxxx");
		var pre = elt("pre", [anchor]);
		removeChildrenAndAdd(display.measure, pre);
		var rect = anchor.getBoundingClientRect(), width = (rect.right - rect.left) / 10;
		if (width > 2) display.cachedCharWidth = width;
		return width || 10;
	}

	// OPERATIONS

	// Operations are used to wrap a series of changes to the editor
	// state in such a way that each change won't have to update the
	// cursor and display (which would be awkward, slow, and
	// error-prone). Instead, display updates are batched and then all
	// combined and executed at once.

	var nextOpId = 0;
	// Start a new operation.
	function startOperation(cm) {
		cm.curOp = {
			viewChanged: false,      // Flag that indicates that lines might need to be redrawn
			startHeight: cm.doc.height, // Used to detect need to update scrollbar
			forceUpdate: false,      // Used to force a redraw
			updateInput: null,       // Whether to reset the input textarea
			typing: false,           // Whether this reset should be careful to leave existing text (for compositing)
			changeObjs: null,        // Accumulated changes, for firing change events
			cursorActivityHandlers: null, // Set of handlers to fire cursorActivity on
			selectionChanged: false, // Whether the selection needs to be redrawn
			updateMaxLine: false,    // Set when the widest line needs to be determined anew
			scrollLeft: null, scrollTop: null, // Intermediate scroll position, not pushed to DOM yet
			scrollToPos: null,       // Used to scroll to a specific position
			id: ++nextOpId           // Unique ID
		};
		if (!delayedCallbackDepth++) delayedCallbacks = [];
	}

	// Finish an operation, updating the display and signalling delayed events
	function endOperation(cm) {
		var op = cm.curOp, doc = cm.doc, display = cm.display;
		cm.curOp = null;

		if (op.updateMaxLine) findMaxLine(cm);

		// If it looks like an update might be needed, call updateDisplay
		if (op.viewChanged || op.forceUpdate || op.scrollTop != null ||
			op.scrollToPos && (op.scrollToPos.from.line < display.viewFrom ||
			op.scrollToPos.to.line >= display.viewTo) ||
			display.maxLineChanged && cm.options.lineWrapping) {
			var updated = updateDisplay(cm, {top: op.scrollTop, ensure: op.scrollToPos}, op.forceUpdate);
			if (cm.display.scroller.offsetHeight) cm.doc.scrollTop = cm.display.scroller.scrollTop;
		}
		// If no update was run, but the selection changed, redraw that.
		if (!updated && op.selectionChanged) updateSelection(cm);
		if (!updated && op.startHeight != cm.doc.height) updateScrollbars(cm);

		// Abort mouse wheel delta measurement, when scrolling explicitly
		if (display.wheelStartX != null && (op.scrollTop != null || op.scrollLeft != null || op.scrollToPos))
			display.wheelStartX = display.wheelStartY = null;

		// Propagate the scroll position to the actual DOM scroller
		if (op.scrollTop != null && display.scroller.scrollTop != op.scrollTop) {
			var top = Math.max(0, Math.min(display.scroller.scrollHeight - display.scroller.clientHeight, op.scrollTop));
			display.scroller.scrollTop = display.scrollbarV.scrollTop = doc.scrollTop = top;
		}
		if (op.scrollLeft != null && display.scroller.scrollLeft != op.scrollLeft) {
			var left = Math.max(0, Math.min(display.scroller.scrollWidth - display.scroller.clientWidth, op.scrollLeft));
			display.scroller.scrollLeft = display.scrollbarH.scrollLeft = doc.scrollLeft = left;
			alignHorizontally(cm);
		}
		// If we need to scroll a specific position into view, do so.
		if (op.scrollToPos) {
			var coords = scrollPosIntoView(cm, clipPos(cm.doc, op.scrollToPos.from),
				clipPos(cm.doc, op.scrollToPos.to), op.scrollToPos.margin);
			if (op.scrollToPos.isCursor && cm.state.focused) maybeScrollWindow(cm, coords);
		}

		if (op.selectionChanged) restartBlink(cm);

		if (cm.state.focused && op.updateInput)
			resetInput(cm, op.typing);

		// Fire events for markers that are hidden/unidden by editing or
		// undoing
		var hidden = op.maybeHiddenMarkers, unhidden = op.maybeUnhiddenMarkers;
		if (hidden) for (var i = 0; i < hidden.length; ++i)
			if (!hidden[i].lines.length) signal(hidden[i], "hide");
		if (unhidden) for (var i = 0; i < unhidden.length; ++i)
			if (unhidden[i].lines.length) signal(unhidden[i], "unhide");

		var delayed;
		if (!--delayedCallbackDepth) {
			delayed = delayedCallbacks;
			delayedCallbacks = null;
		}
		// Fire change events, and delayed event handlers
		if (op.changeObjs)
			signal(cm, "changes", cm, op.changeObjs);
		if (delayed) for (var i = 0; i < delayed.length; ++i) delayed[i]();
		if (op.cursorActivityHandlers)
			for (var i = 0; i < op.cursorActivityHandlers.length; i++)
				op.cursorActivityHandlers[i](cm);
	}

	// Run the given function in an operation
	function runInOp(cm, f) {
		if (cm.curOp) return f();
		startOperation(cm);
		try { return f(); }
		finally { endOperation(cm); }
	}
	// Wraps a function in an operation. Returns the wrapped function.
	function operation(cm, f) {
		return function() {
			if (cm.curOp) return f.apply(cm, arguments);
			startOperation(cm);
			try { return f.apply(cm, arguments); }
			finally { endOperation(cm); }
		};
	}
	// Used to add methods to editor and doc instances, wrapping them in
	// operations.
	function methodOp(f) {
		return function() {
			if (this.curOp) return f.apply(this, arguments);
			startOperation(this);
			try { return f.apply(this, arguments); }
			finally { endOperation(this); }
		};
	}
	function docMethodOp(f) {
		return function() {
			var cm = this.cm;
			if (!cm || cm.curOp) return f.apply(this, arguments);
			startOperation(cm);
			try { return f.apply(this, arguments); }
			finally { endOperation(cm); }
		};
	}

	// VIEW TRACKING

	// These objects are used to represent the visible (currently drawn)
	// part of the document. A LineView may correspond to multiple
	// logical lines, if those are connected by collapsed ranges.
	function LineView(doc, line, lineN) {
		// The starting line
		this.line = line;
		// Continuing lines, if any
		this.rest = visualLineContinued(line);
		// Number of logical lines in this visual line
		this.size = this.rest ? lineNo(lst(this.rest)) - lineN + 1 : 1;
		this.node = this.text = null;
		this.hidden = lineIsHidden(doc, line);
	}

	// Create a range of LineView objects for the given lines.
	function buildViewArray(cm, from, to) {
		var array = [], nextPos;
		for (var pos = from; pos < to; pos = nextPos) {
			var view = new LineView(cm.doc, getLine(cm.doc, pos), pos);
			nextPos = pos + view.size;
			array.push(view);
		}
		return array;
	}

	// Updates the display.view data structure for a given change to the
	// document. From and to are in pre-change coordinates. Lendiff is
	// the amount of lines added or subtracted by the change. This is
	// used for changes that span multiple lines, or change the way
	// lines are divided into visual lines. regLineChange (below)
	// registers single-line changes.
	function regChange(cm, from, to, lendiff) {
		if (from == null) from = cm.doc.first;
		if (to == null) to = cm.doc.first + cm.doc.size;
		if (!lendiff) lendiff = 0;

		var display = cm.display;
		if (lendiff && to < display.viewTo &&
			(display.updateLineNumbers == null || display.updateLineNumbers > from))
			display.updateLineNumbers = from;

		cm.curOp.viewChanged = true;

		if (from >= display.viewTo) { // Change after
			if (sawCollapsedSpans && visualLineNo(cm.doc, from) < display.viewTo)
				resetView(cm);
		} else if (to <= display.viewFrom) { // Change before
			if (sawCollapsedSpans && visualLineEndNo(cm.doc, to + lendiff) > display.viewFrom) {
				resetView(cm);
			} else {
				display.viewFrom += lendiff;
				display.viewTo += lendiff;
			}
		} else if (from <= display.viewFrom && to >= display.viewTo) { // Full overlap
			resetView(cm);
		} else if (from <= display.viewFrom) { // Top overlap
			var cut = viewCuttingPoint(cm, to, to + lendiff, 1);
			if (cut) {
				display.view = display.view.slice(cut.index);
				display.viewFrom = cut.lineN;
				display.viewTo += lendiff;
			} else {
				resetView(cm);
			}
		} else if (to >= display.viewTo) { // Bottom overlap
			var cut = viewCuttingPoint(cm, from, from, -1);
			if (cut) {
				display.view = display.view.slice(0, cut.index);
				display.viewTo = cut.lineN;
			} else {
				resetView(cm);
			}
		} else { // Gap in the middle
			var cutTop = viewCuttingPoint(cm, from, from, -1);
			var cutBot = viewCuttingPoint(cm, to, to + lendiff, 1);
			if (cutTop && cutBot) {
				display.view = display.view.slice(0, cutTop.index)
					.concat(buildViewArray(cm, cutTop.lineN, cutBot.lineN))
					.concat(display.view.slice(cutBot.index));
				display.viewTo += lendiff;
			} else {
				resetView(cm);
			}
		}

		var ext = display.externalMeasured;
		if (ext) {
			if (to < ext.lineN)
				ext.lineN += lendiff;
			else if (from < ext.lineN + ext.size)
				display.externalMeasured = null;
		}
	}

	// Register a change to a single line. Type must be one of "text",
	// "gutter", "class", "widget"
	function regLineChange(cm, line, type) {
		cm.curOp.viewChanged = true;
		var display = cm.display, ext = cm.display.externalMeasured;
		if (ext && line >= ext.lineN && line < ext.lineN + ext.size)
			display.externalMeasured = null;

		if (line < display.viewFrom || line >= display.viewTo) return;
		var lineView = display.view[findViewIndex(cm, line)];
		if (lineView.node == null) return;
		var arr = lineView.changes || (lineView.changes = []);
		if (indexOf(arr, type) == -1) arr.push(type);
	}

	// Clear the view.
	function resetView(cm) {
		cm.display.viewFrom = cm.display.viewTo = cm.doc.first;
		cm.display.view = [];
		cm.display.viewOffset = 0;
	}

	// Find the view element corresponding to a given line. Return null
	// when the line isn't visible.
	function findViewIndex(cm, n) {
		if (n >= cm.display.viewTo) return null;
		n -= cm.display.viewFrom;
		if (n < 0) return null;
		var view = cm.display.view;
		for (var i = 0; i < view.length; i++) {
			n -= view[i].size;
			if (n < 0) return i;
		}
	}

	function viewCuttingPoint(cm, oldN, newN, dir) {
		var index = findViewIndex(cm, oldN), diff, view = cm.display.view;
		if (!sawCollapsedSpans || newN == cm.doc.first + cm.doc.size)
			return {index: index, lineN: newN};
		for (var i = 0, n = cm.display.viewFrom; i < index; i++)
			n += view[i].size;
		if (n != oldN) {
			if (dir > 0) {
				if (index == view.length - 1) return null;
				diff = (n + view[index].size) - oldN;
				index++;
			} else {
				diff = n - oldN;
			}
			oldN += diff; newN += diff;
		}
		while (visualLineNo(cm.doc, newN) != newN) {
			if (index == (dir < 0 ? 0 : view.length - 1)) return null;
			newN += dir * view[index - (dir < 0 ? 1 : 0)].size;
			index += dir;
		}
		return {index: index, lineN: newN};
	}

	// Force the view to cover a given range, adding empty view element
	// or clipping off existing ones as needed.
	function adjustView(cm, from, to) {
		var display = cm.display, view = display.view;
		if (view.length == 0 || from >= display.viewTo || to <= display.viewFrom) {
			display.view = buildViewArray(cm, from, to);
			display.viewFrom = from;
		} else {
			if (display.viewFrom > from)
				display.view = buildViewArray(cm, from, display.viewFrom).concat(display.view);
			else if (display.viewFrom < from)
				display.view = display.view.slice(findViewIndex(cm, from));
			display.viewFrom = from;
			if (display.viewTo < to)
				display.view = display.view.concat(buildViewArray(cm, display.viewTo, to));
			else if (display.viewTo > to)
				display.view = display.view.slice(0, findViewIndex(cm, to));
		}
		display.viewTo = to;
	}

	// Count the number of lines in the view whose DOM representation is
	// out of date (or nonexistent).
	function countDirtyView(cm) {
		var view = cm.display.view, dirty = 0;
		for (var i = 0; i < view.length; i++) {
			var lineView = view[i];
			if (!lineView.hidden && (!lineView.node || lineView.changes)) ++dirty;
		}
		return dirty;
	}

	// INPUT HANDLING

	// Poll for input changes, using the normal rate of polling. This
	// runs as long as the editor is focused.
	function slowPoll(cm) {
		if (cm.display.pollingFast) return;
		cm.display.poll.set(cm.options.pollInterval, function() {
			readInput(cm);
			if (cm.state.focused) slowPoll(cm);
		});
	}

	// When an event has just come in that is likely to add or change
	// something in the input textarea, we poll faster, to ensure that
	// the change appears on the screen quickly.
	function fastPoll(cm) {
		var missed = false;
		cm.display.pollingFast = true;
		function p() {
			var changed = readInput(cm);
			if (!changed && !missed) {missed = true; cm.display.poll.set(60, p);}
			else {cm.display.pollingFast = false; slowPoll(cm);}
		}
		cm.display.poll.set(20, p);
	}

	// Read input from the textarea, and update the document to match.
	// When something is selected, it is present in the textarea, and
	// selected (unless it is huge, in which case a placeholder is
	// used). When nothing is selected, the cursor sits after previously
	// seen text (can be empty), which is stored in prevInput (we must
	// not reset the textarea when typing, because that breaks IME).
	function readInput(cm) {
		var input = cm.display.input, prevInput = cm.display.prevInput, doc = cm.doc;
		// Since this is called a *lot*, try to bail out as cheaply as
		// possible when it is clear that nothing happened. hasSelection
		// will be the case when there is a lot of text in the textarea,
		// in which case reading its value would be expensive.
		if (!cm.state.focused || (hasSelection(input) && !prevInput) || isReadOnly(cm) || cm.options.disableInput)
			return false;
		// See paste handler for more on the fakedLastChar kludge
		if (cm.state.pasteIncoming && cm.state.fakedLastChar) {
			input.value = input.value.substring(0, input.value.length - 1);
			cm.state.fakedLastChar = false;
		}
		var text = input.value;
		// If nothing changed, bail.
		if (text == prevInput && !cm.somethingSelected()) return false;
		// Work around nonsensical selection resetting in IE9/10
		if (ie && ie_version >= 9 && cm.display.inputHasSelection === text) {
			resetInput(cm);
			return false;
		}

		var withOp = !cm.curOp;
		if (withOp) startOperation(cm);
		cm.display.shift = false;

		if (text.charCodeAt(0) == 0x200b && doc.sel == cm.display.selForContextMenu && !prevInput)
			prevInput = "\u200b";
		// Find the part of the input that is actually new
		var same = 0, l = Math.min(prevInput.length, text.length);
		while (same < l && prevInput.charCodeAt(same) == text.charCodeAt(same)) ++same;
		var inserted = text.slice(same), textLines = splitLines(inserted);

		// When pasing N lines into N selections, insert one line per selection
		var multiPaste = cm.state.pasteIncoming && textLines.length > 1 && doc.sel.ranges.length == textLines.length;

		// Normal behavior is to insert the new text into every selection
		for (var i = doc.sel.ranges.length - 1; i >= 0; i--) {
			var range = doc.sel.ranges[i];
			var from = range.from(), to = range.to();
			// Handle deletion
			if (same < prevInput.length)
				from = Pos(from.line, from.ch - (prevInput.length - same));
			// Handle overwrite
			else if (cm.state.overwrite && range.empty() && !cm.state.pasteIncoming)
				to = Pos(to.line, Math.min(getLine(doc, to.line).text.length, to.ch + lst(textLines).length));
			var updateInput = cm.curOp.updateInput;
			var changeEvent = {from: from, to: to, text: multiPaste ? [textLines[i]] : textLines,
				origin: cm.state.pasteIncoming ? "paste" : cm.state.cutIncoming ? "cut" : "+input"};
			makeChange(cm.doc, changeEvent);
			signalLater(cm, "inputRead", cm, changeEvent);
			// When an 'electric' character is inserted, immediately trigger a reindent
			if (inserted && !cm.state.pasteIncoming && cm.options.electricChars &&
				cm.options.smartIndent && range.head.ch < 100 &&
				(!i || doc.sel.ranges[i - 1].head.line != range.head.line)) {
				var mode = cm.getModeAt(range.head);
				if (mode.electricChars) {
					for (var j = 0; j < mode.electricChars.length; j++)
						if (inserted.indexOf(mode.electricChars.charAt(j)) > -1) {
							indentLine(cm, range.head.line, "smart");
							break;
						}
				} else if (mode.electricInput) {
					var end = changeEnd(changeEvent);
					if (mode.electricInput.test(getLine(doc, end.line).text.slice(0, end.ch)))
						indentLine(cm, range.head.line, "smart");
				}
			}
		}
		ensureCursorVisible(cm);
		cm.curOp.updateInput = updateInput;
		cm.curOp.typing = true;

		// Don't leave long text in the textarea, since it makes further polling slow
		if (text.length > 1000 || text.indexOf("\n") > -1) input.value = cm.display.prevInput = "";
		else cm.display.prevInput = text;
		if (withOp) endOperation(cm);
		cm.state.pasteIncoming = cm.state.cutIncoming = false;
		return true;
	}

	// Reset the input to correspond to the selection (or to be empty,
	// when not typing and nothing is selected)
	function resetInput(cm, typing) {
		var minimal, selected, doc = cm.doc;
		if (cm.somethingSelected()) {
			cm.display.prevInput = "";
			var range = doc.sel.primary();
			minimal = hasCopyEvent &&
				(range.to().line - range.from().line > 100 || (selected = cm.getSelection()).length > 1000);
			var content = minimal ? "-" : selected || cm.getSelection();
			cm.display.input.value = content;
			if (cm.state.focused) selectInput(cm.display.input);
			if (ie && ie_version >= 9) cm.display.inputHasSelection = content;
		} else if (!typing) {
			cm.display.prevInput = cm.display.input.value = "";
			if (ie && ie_version >= 9) cm.display.inputHasSelection = null;
		}
		cm.display.inaccurateSelection = minimal;
	}

	function focusInput(cm) {
		if (cm.options.readOnly != "nocursor" && (!mobile || activeElt() != cm.display.input))
			cm.display.input.focus();
	}

	function ensureFocus(cm) {
		if (!cm.state.focused) { focusInput(cm); onFocus(cm); }
	}

	function isReadOnly(cm) {
		return cm.options.readOnly || cm.doc.cantEdit;
	}

	// EVENT HANDLERS

	// Attach the necessary event handlers when initializing the editor
	function registerEventHandlers(cm) {
		var d = cm.display;
		on(d.scroller, "mousedown", operation(cm, onMouseDown));
		// Older IE's will not fire a second mousedown for a double click
		if (ie && ie_version < 11)
			on(d.scroller, "dblclick", operation(cm, function(e) {
				if (signalDOMEvent(cm, e)) return;
				var pos = posFromMouse(cm, e);
				if (!pos || clickInGutter(cm, e) || eventInWidget(cm.display, e)) return;
				e_preventDefault(e);
				var word = findWordAt(cm, pos);
				extendSelection(cm.doc, word.anchor, word.head);
			}));
		else
			on(d.scroller, "dblclick", function(e) { signalDOMEvent(cm, e) || e_preventDefault(e); });
		// Prevent normal selection in the editor (we handle our own)
		on(d.lineSpace, "selectstart", function(e) {
			if (!eventInWidget(d, e)) e_preventDefault(e);
		});
		// Some browsers fire contextmenu *after* opening the menu, at
		// which point we can't mess with it anymore. Context menu is
		// handled in onMouseDown for these browsers.
		if (!captureRightClick) on(d.scroller, "contextmenu", function(e) {onContextMenu(cm, e);});

		// Sync scrolling between fake scrollbars and real scrollable
		// area, ensure viewport is updated when scrolling.
		on(d.scroller, "scroll", function() {
			if (d.scroller.clientHeight) {
				setScrollTop(cm, d.scroller.scrollTop);
				setScrollLeft(cm, d.scroller.scrollLeft, true);
				signal(cm, "scroll", cm);
			}
		});
		on(d.scrollbarV, "scroll", function() {
			if (d.scroller.clientHeight) setScrollTop(cm, d.scrollbarV.scrollTop);
		});
		on(d.scrollbarH, "scroll", function() {
			if (d.scroller.clientHeight) setScrollLeft(cm, d.scrollbarH.scrollLeft);
		});

		// Listen to wheel events in order to try and update the viewport on time.
		on(d.scroller, "mousewheel", function(e){onScrollWheel(cm, e);});
		on(d.scroller, "DOMMouseScroll", function(e){onScrollWheel(cm, e);});

		// Prevent clicks in the scrollbars from killing focus
		function reFocus() { if (cm.state.focused) setTimeout(bind(focusInput, cm), 0); }
		on(d.scrollbarH, "mousedown", reFocus);
		on(d.scrollbarV, "mousedown", reFocus);
		// Prevent wrapper from ever scrolling
		on(d.wrapper, "scroll", function() { d.wrapper.scrollTop = d.wrapper.scrollLeft = 0; });

		on(d.input, "keyup", operation(cm, onKeyUp));
		on(d.input, "input", function() {
			if (ie && ie_version >= 9 && cm.display.inputHasSelection) cm.display.inputHasSelection = null;
			fastPoll(cm);
		});
		on(d.input, "keydown", operation(cm, onKeyDown));
		on(d.input, "keypress", operation(cm, onKeyPress));
		on(d.input, "focus", bind(onFocus, cm));
		on(d.input, "blur", bind(onBlur, cm));

		function drag_(e) {
			if (!signalDOMEvent(cm, e)) e_stop(e);
		}
		if (cm.options.dragDrop) {
			on(d.scroller, "dragstart", function(e){onDragStart(cm, e);});
			on(d.scroller, "dragenter", drag_);
			on(d.scroller, "dragover", drag_);
			on(d.scroller, "drop", operation(cm, onDrop));
		}
		on(d.scroller, "paste", function(e) {
			if (eventInWidget(d, e)) return;
			cm.state.pasteIncoming = true;
			focusInput(cm);
			fastPoll(cm);
		});
		on(d.input, "paste", function() {
			// Workaround for webkit bug https://bugs.webkit.org/show_bug.cgi?id=90206
			// Add a char to the end of textarea before paste occur so that
			// selection doesn't span to the end of textarea.
			if (webkit && !cm.state.fakedLastChar && !(new Date - cm.state.lastMiddleDown < 200)) {
				var start = d.input.selectionStart, end = d.input.selectionEnd;
				d.input.value += "$";
				// The selection end needs to be set before the start, otherwise there
				// can be an intermediate non-empty selection between the two, which
				// can override the middle-click paste buffer on linux and cause the
				// wrong thing to get pasted.
				d.input.selectionEnd = end;
				d.input.selectionStart = start;
				cm.state.fakedLastChar = true;
			}
			cm.state.pasteIncoming = true;
			fastPoll(cm);
		});

		function prepareCopyCut(e) {
			if (cm.somethingSelected()) {
				if (d.inaccurateSelection) {
					d.prevInput = "";
					d.inaccurateSelection = false;
					d.input.value = cm.getSelection();
					selectInput(d.input);
				}
			} else {
				var text = "", ranges = [];
				for (var i = 0; i < cm.doc.sel.ranges.length; i++) {
					var line = cm.doc.sel.ranges[i].head.line;
					var lineRange = {anchor: Pos(line, 0), head: Pos(line + 1, 0)};
					ranges.push(lineRange);
					text += cm.getRange(lineRange.anchor, lineRange.head);
				}
				if (e.type == "cut") {
					cm.setSelections(ranges, null, sel_dontScroll);
				} else {
					d.prevInput = "";
					d.input.value = text;
					selectInput(d.input);
				}
			}
			if (e.type == "cut") cm.state.cutIncoming = true;
		}
		on(d.input, "cut", prepareCopyCut);
		on(d.input, "copy", prepareCopyCut);

		// Needed to handle Tab key in KHTML
		if (khtml) on(d.sizer, "mouseup", function() {
			if (activeElt() == d.input) d.input.blur();
			focusInput(cm);
		});
	}

	// Called when the window resizes
	function onResize(cm) {
		// Might be a text scaling operation, clear size caches.
		var d = cm.display;
		d.cachedCharWidth = d.cachedTextHeight = d.cachedPaddingH = null;
		cm.setSize();
	}

	// MOUSE EVENTS

	// Return true when the given mouse event happened in a widget
	function eventInWidget(display, e) {
		for (var n = e_target(e); n != display.wrapper; n = n.parentNode) {
			if (!n || n.ignoreEvents || n.parentNode == display.sizer && n != display.mover) return true;
		}
	}

	// Given a mouse event, find the corresponding position. If liberal
	// is false, it checks whether a gutter or scrollbar was clicked,
	// and returns null if it was. forRect is used by rectangular
	// selections, and tries to estimate a character position even for
	// coordinates beyond the right of the text.
	function posFromMouse(cm, e, liberal, forRect) {
		var display = cm.display;
		if (!liberal) {
			var target = e_target(e);
			if (target == display.scrollbarH || target == display.scrollbarV ||
				target == display.scrollbarFiller || target == display.gutterFiller) return null;
		}
		var x, y, space = display.lineSpace.getBoundingClientRect();
		// Fails unpredictably on IE[67] when mouse is dragged around quickly.
		try { x = e.clientX - space.left; y = e.clientY - space.top; }
		catch (e) { return null; }
		var coords = coordsChar(cm, x, y), line;
		if (forRect && coords.xRel == 1 && (line = getLine(cm.doc, coords.line).text).length == coords.ch) {
			var colDiff = countColumn(line, line.length, cm.options.tabSize) - line.length;
			coords = Pos(coords.line, Math.max(0, Math.round((x - paddingH(cm.display).left) / charWidth(cm.display)) - colDiff));
		}
		return coords;
	}

	// A mouse down can be a single click, double click, triple click,
	// start of selection drag, start of text drag, new cursor
	// (ctrl-click), rectangle drag (alt-drag), or xwin
	// middle-click-paste. Or it might be a click on something we should
	// not interfere with, such as a scrollbar or widget.
	function onMouseDown(e) {
		if (signalDOMEvent(this, e)) return;
		var cm = this, display = cm.display;
		display.shift = e.shiftKey;

		if (eventInWidget(display, e)) {
			if (!webkit) {
				// Briefly turn off draggability, to allow widgets to do
				// normal dragging things.
				display.scroller.draggable = false;
				setTimeout(function(){display.scroller.draggable = true;}, 100);
			}
			return;
		}
		if (clickInGutter(cm, e)) return;
		var start = posFromMouse(cm, e);
		window.focus();

		switch (e_button(e)) {
			case 1:
				if (start)
					leftButtonDown(cm, e, start);
				else if (e_target(e) == display.scroller)
					e_preventDefault(e);
				break;
			case 2:
				if (webkit) cm.state.lastMiddleDown = +new Date;
				if (start) extendSelection(cm.doc, start);
				setTimeout(bind(focusInput, cm), 20);
				e_preventDefault(e);
				break;
			case 3:
				if (captureRightClick) onContextMenu(cm, e);
				break;
		}
	}

	var lastClick, lastDoubleClick;
	function leftButtonDown(cm, e, start) {
		setTimeout(bind(ensureFocus, cm), 0);

		var now = +new Date, type;
		if (lastDoubleClick && lastDoubleClick.time > now - 400 && cmp(lastDoubleClick.pos, start) == 0) {
			type = "triple";
		} else if (lastClick && lastClick.time > now - 400 && cmp(lastClick.pos, start) == 0) {
			type = "double";
			lastDoubleClick = {time: now, pos: start};
		} else {
			type = "single";
			lastClick = {time: now, pos: start};
		}

		var sel = cm.doc.sel, modifier = mac ? e.metaKey : e.ctrlKey;
		if (cm.options.dragDrop && dragAndDrop && !isReadOnly(cm) &&
			type == "single" && sel.contains(start) > -1 && sel.somethingSelected())
			leftButtonStartDrag(cm, e, start, modifier);
		else
			leftButtonSelect(cm, e, start, type, modifier);
	}

	// Start a text drag. When it ends, see if any dragging actually
	// happen, and treat as a click if it didn't.
	function leftButtonStartDrag(cm, e, start, modifier) {
		var display = cm.display;
		var dragEnd = operation(cm, function(e2) {
			if (webkit) display.scroller.draggable = false;
			cm.state.draggingText = false;
			off(document, "mouseup", dragEnd);
			off(display.scroller, "drop", dragEnd);
			if (Math.abs(e.clientX - e2.clientX) + Math.abs(e.clientY - e2.clientY) < 10) {
				e_preventDefault(e2);
				if (!modifier)
					extendSelection(cm.doc, start);
				focusInput(cm);
				// Work around unexplainable focus problem in IE9 (#2127)
				if (ie && ie_version == 9)
					setTimeout(function() {document.body.focus(); focusInput(cm);}, 20);
			}
		});
		// Let the drag handler handle this.
		if (webkit) display.scroller.draggable = true;
		cm.state.draggingText = dragEnd;
		// IE's approach to draggable
		if (display.scroller.dragDrop) display.scroller.dragDrop();
		on(document, "mouseup", dragEnd);
		on(display.scroller, "drop", dragEnd);
	}

	// Normal selection, as opposed to text dragging.
	function leftButtonSelect(cm, e, start, type, addNew) {
		var display = cm.display, doc = cm.doc;
		e_preventDefault(e);

		var ourRange, ourIndex, startSel = doc.sel;
		if (addNew && !e.shiftKey) {
			ourIndex = doc.sel.contains(start);
			if (ourIndex > -1)
				ourRange = doc.sel.ranges[ourIndex];
			else
				ourRange = new Range(start, start);
		} else {
			ourRange = doc.sel.primary();
		}

		if (e.altKey) {
			type = "rect";
			if (!addNew) ourRange = new Range(start, start);
			start = posFromMouse(cm, e, true, true);
			ourIndex = -1;
		} else if (type == "double") {
			var word = findWordAt(cm, start);
			if (cm.display.shift || doc.extend)
				ourRange = extendRange(doc, ourRange, word.anchor, word.head);
			else
				ourRange = word;
		} else if (type == "triple") {
			var line = new Range(Pos(start.line, 0), clipPos(doc, Pos(start.line + 1, 0)));
			if (cm.display.shift || doc.extend)
				ourRange = extendRange(doc, ourRange, line.anchor, line.head);
			else
				ourRange = line;
		} else {
			ourRange = extendRange(doc, ourRange, start);
		}

		if (!addNew) {
			ourIndex = 0;
			setSelection(doc, new Selection([ourRange], 0), sel_mouse);
			startSel = doc.sel;
		} else if (ourIndex > -1) {
			replaceOneSelection(doc, ourIndex, ourRange, sel_mouse);
		} else {
			ourIndex = doc.sel.ranges.length;
			setSelection(doc, normalizeSelection(doc.sel.ranges.concat([ourRange]), ourIndex),
				{scroll: false, origin: "*mouse"});
		}

		var lastPos = start;
		function extendTo(pos) {
			if (cmp(lastPos, pos) == 0) return;
			lastPos = pos;

			if (type == "rect") {
				var ranges = [], tabSize = cm.options.tabSize;
				var startCol = countColumn(getLine(doc, start.line).text, start.ch, tabSize);
				var posCol = countColumn(getLine(doc, pos.line).text, pos.ch, tabSize);
				var left = Math.min(startCol, posCol), right = Math.max(startCol, posCol);
				for (var line = Math.min(start.line, pos.line), end = Math.min(cm.lastLine(), Math.max(start.line, pos.line));
					 line <= end; line++) {
					var text = getLine(doc, line).text, leftPos = findColumn(text, left, tabSize);
					if (left == right)
						ranges.push(new Range(Pos(line, leftPos), Pos(line, leftPos)));
					else if (text.length > leftPos)
						ranges.push(new Range(Pos(line, leftPos), Pos(line, findColumn(text, right, tabSize))));
				}
				if (!ranges.length) ranges.push(new Range(start, start));
				setSelection(doc, normalizeSelection(startSel.ranges.slice(0, ourIndex).concat(ranges), ourIndex),
					{origin: "*mouse", scroll: false});
				cm.scrollIntoView(pos);
			} else {
				var oldRange = ourRange;
				var anchor = oldRange.anchor, head = pos;
				if (type != "single") {
					if (type == "double")
						var range = findWordAt(cm, pos);
					else
						var range = new Range(Pos(pos.line, 0), clipPos(doc, Pos(pos.line + 1, 0)));
					if (cmp(range.anchor, anchor) > 0) {
						head = range.head;
						anchor = minPos(oldRange.from(), range.anchor);
					} else {
						head = range.anchor;
						anchor = maxPos(oldRange.to(), range.head);
					}
				}
				var ranges = startSel.ranges.slice(0);
				ranges[ourIndex] = new Range(clipPos(doc, anchor), head);
				setSelection(doc, normalizeSelection(ranges, ourIndex), sel_mouse);
			}
		}

		var editorSize = display.wrapper.getBoundingClientRect();
		// Used to ensure timeout re-tries don't fire when another extend
		// happened in the meantime (clearTimeout isn't reliable -- at
		// least on Chrome, the timeouts still happen even when cleared,
		// if the clear happens after their scheduled firing time).
		var counter = 0;

		function extend(e) {
			var curCount = ++counter;
			var cur = posFromMouse(cm, e, true, type == "rect");
			if (!cur) return;
			if (cmp(cur, lastPos) != 0) {
				ensureFocus(cm);
				extendTo(cur);
				var visible = visibleLines(display, doc);
				if (cur.line >= visible.to || cur.line < visible.from)
					setTimeout(operation(cm, function(){if (counter == curCount) extend(e);}), 150);
			} else {
				var outside = e.clientY < editorSize.top ? -20 : e.clientY > editorSize.bottom ? 20 : 0;
				if (outside) setTimeout(operation(cm, function() {
					if (counter != curCount) return;
					display.scroller.scrollTop += outside;
					extend(e);
				}), 50);
			}
		}

		function done(e) {
			counter = Infinity;
			e_preventDefault(e);
			focusInput(cm);
			off(document, "mousemove", move);
			off(document, "mouseup", up);
			doc.history.lastSelOrigin = null;
		}

		var move = operation(cm, function(e) {
			if (!e_button(e)) done(e);
			else extend(e);
		});
		var up = operation(cm, done);
		on(document, "mousemove", move);
		on(document, "mouseup", up);
	}

	// Determines whether an event happened in the gutter, and fires the
	// handlers for the corresponding event.
	function gutterEvent(cm, e, type, prevent, signalfn) {
		try { var mX = e.clientX, mY = e.clientY; }
		catch(e) { return false; }
		if (mX >= Math.floor(cm.display.gutters.getBoundingClientRect().right)) return false;
		if (prevent) e_preventDefault(e);

		var display = cm.display;
		var lineBox = display.lineDiv.getBoundingClientRect();

		if (mY > lineBox.bottom || !hasHandler(cm, type)) return e_defaultPrevented(e);
		mY -= lineBox.top - display.viewOffset;

		for (var i = 0; i < cm.options.gutters.length; ++i) {
			var g = display.gutters.childNodes[i];
			if (g && g.getBoundingClientRect().right >= mX) {
				var line = lineAtHeight(cm.doc, mY);
				var gutter = cm.options.gutters[i];
				signalfn(cm, type, cm, line, gutter, e);
				return e_defaultPrevented(e);
			}
		}
	}

	function clickInGutter(cm, e) {
		return gutterEvent(cm, e, "gutterClick", true, signalLater);
	}

	// Kludge to work around strange IE behavior where it'll sometimes
	// re-fire a series of drag-related events right after the drop (#1551)
	var lastDrop = 0;

	function onDrop(e) {
		var cm = this;
		if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e))
			return;
		e_preventDefault(e);
		if (ie) lastDrop = +new Date;
		var pos = posFromMouse(cm, e, true), files = e.dataTransfer.files;
		if (!pos || isReadOnly(cm)) return;
		// Might be a file drop, in which case we simply extract the text
		// and insert it.
		if (files && files.length && window.FileReader && window.File) {
			var n = files.length, text = Array(n), read = 0;
			var loadFile = function(file, i) {
				var reader = new FileReader;
				reader.onload = operation(cm, function() {
					text[i] = reader.result;
					if (++read == n) {
						pos = clipPos(cm.doc, pos);
						var change = {from: pos, to: pos, text: splitLines(text.join("\n")), origin: "paste"};
						makeChange(cm.doc, change);
						setSelectionReplaceHistory(cm.doc, simpleSelection(pos, changeEnd(change)));
					}
				});
				reader.readAsText(file);
			};
			for (var i = 0; i < n; ++i) loadFile(files[i], i);
		} else { // Normal drop
			// Don't do a replace if the drop happened inside of the selected text.
			if (cm.state.draggingText && cm.doc.sel.contains(pos) > -1) {
				cm.state.draggingText(e);
				// Ensure the editor is re-focused
				setTimeout(bind(focusInput, cm), 20);
				return;
			}
			try {
				var text = e.dataTransfer.getData("Text");
				if (text) {
					if (cm.state.draggingText && !(mac ? e.metaKey : e.ctrlKey))
						var selected = cm.listSelections();
					setSelectionNoUndo(cm.doc, simpleSelection(pos, pos));
					if (selected) for (var i = 0; i < selected.length; ++i)
						replaceRange(cm.doc, "", selected[i].anchor, selected[i].head, "drag");
					cm.replaceSelection(text, "around", "paste");
					focusInput(cm);
				}
			}
			catch(e){}
		}
	}

	function onDragStart(cm, e) {
		if (ie && (!cm.state.draggingText || +new Date - lastDrop < 100)) { e_stop(e); return; }
		if (signalDOMEvent(cm, e) || eventInWidget(cm.display, e)) return;

		e.dataTransfer.setData("Text", cm.getSelection());

		// Use dummy image instead of default browsers image.
		// Recent Safari (~6.0.2) have a tendency to segfault when this happens, so we don't do it there.
		if (e.dataTransfer.setDragImage && !safari) {
			var img = elt("img", null, null, "position: fixed; left: 0; top: 0;");
			img.src = "";
			if (presto) {
				img.width = img.height = 1;
				cm.display.wrapper.appendChild(img);
				// Force a relayout, or Opera won't use our image for some obscure reason
				img._top = img.offsetTop;
			}
			e.dataTransfer.setDragImage(img, 0, 0);
			if (presto) img.parentNode.removeChild(img);
		}
	}

	// SCROLL EVENTS

	// Sync the scrollable area and scrollbars, ensure the viewport
	// covers the visible area.
	function setScrollTop(cm, val) {
		if (Math.abs(cm.doc.scrollTop - val) < 2) return;
		cm.doc.scrollTop = val;
		if (!gecko) updateDisplay(cm, {top: val});
		if (cm.display.scroller.scrollTop != val) cm.display.scroller.scrollTop = val;
		if (cm.display.scrollbarV.scrollTop != val) cm.display.scrollbarV.scrollTop = val;
		if (gecko) updateDisplay(cm);
		startWorker(cm, 100);
	}
	// Sync scroller and scrollbar, ensure the gutter elements are
	// aligned.
	function setScrollLeft(cm, val, isScroller) {
		if (isScroller ? val == cm.doc.scrollLeft : Math.abs(cm.doc.scrollLeft - val) < 2) return;
		val = Math.min(val, cm.display.scroller.scrollWidth - cm.display.scroller.clientWidth);
		cm.doc.scrollLeft = val;
		alignHorizontally(cm);
		if (cm.display.scroller.scrollLeft != val) cm.display.scroller.scrollLeft = val;
		if (cm.display.scrollbarH.scrollLeft != val) cm.display.scrollbarH.scrollLeft = val;
	}

	// Since the delta values reported on mouse wheel events are
	// unstandardized between browsers and even browser versions, and
	// generally horribly unpredictable, this code starts by measuring
	// the scroll effect that the first few mouse wheel events have,
	// and, from that, detects the way it can convert deltas to pixel
	// offsets afterwards.
	//
	// The reason we want to know the amount a wheel event will scroll
	// is that it gives us a chance to update the display before the
	// actual scrolling happens, reducing flickering.

	var wheelSamples = 0, wheelPixelsPerUnit = null;
	// Fill in a browser-detected starting value on browsers where we
	// know one. These don't have to be accurate -- the result of them
	// being wrong would just be a slight flicker on the first wheel
	// scroll (if it is large enough).
	if (ie) wheelPixelsPerUnit = -.53;
	else if (gecko) wheelPixelsPerUnit = 15;
	else if (chrome) wheelPixelsPerUnit = -.7;
	else if (safari) wheelPixelsPerUnit = -1/3;

	function onScrollWheel(cm, e) {
		var dx = e.wheelDeltaX, dy = e.wheelDeltaY;
		if (dx == null && e.detail && e.axis == e.HORIZONTAL_AXIS) dx = e.detail;
		if (dy == null && e.detail && e.axis == e.VERTICAL_AXIS) dy = e.detail;
		else if (dy == null) dy = e.wheelDelta;

		var display = cm.display, scroll = display.scroller;
		// Quit if there's nothing to scroll here
		if (!(dx && scroll.scrollWidth > scroll.clientWidth ||
			dy && scroll.scrollHeight > scroll.clientHeight)) return;

		// Webkit browsers on OS X abort momentum scrolls when the target
		// of the scroll event is removed from the scrollable element.
		// This hack (see related code in patchDisplay) makes sure the
		// element is kept around.
		if (dy && mac && webkit) {
			outer: for (var cur = e.target, view = display.view; cur != scroll; cur = cur.parentNode) {
				for (var i = 0; i < view.length; i++) {
					if (view[i].node == cur) {
						cm.display.currentWheelTarget = cur;
						break outer;
					}
				}
			}
		}

		// On some browsers, horizontal scrolling will cause redraws to
		// happen before the gutter has been realigned, causing it to
		// wriggle around in a most unseemly way. When we have an
		// estimated pixels/delta value, we just handle horizontal
		// scrolling entirely here. It'll be slightly off from native, but
		// better than glitching out.
		if (dx && !gecko && !presto && wheelPixelsPerUnit != null) {
			if (dy)
				setScrollTop(cm, Math.max(0, Math.min(scroll.scrollTop + dy * wheelPixelsPerUnit, scroll.scrollHeight - scroll.clientHeight)));
			setScrollLeft(cm, Math.max(0, Math.min(scroll.scrollLeft + dx * wheelPixelsPerUnit, scroll.scrollWidth - scroll.clientWidth)));
			e_preventDefault(e);
			display.wheelStartX = null; // Abort measurement, if in progress
			return;
		}

		// 'Project' the visible viewport to cover the area that is being
		// scrolled into view (if we know enough to estimate it).
		if (dy && wheelPixelsPerUnit != null) {
			var pixels = dy * wheelPixelsPerUnit;
			var top = cm.doc.scrollTop, bot = top + display.wrapper.clientHeight;
			if (pixels < 0) top = Math.max(0, top + pixels - 50);
			else bot = Math.min(cm.doc.height, bot + pixels + 50);
			updateDisplay(cm, {top: top, bottom: bot});
		}

		if (wheelSamples < 20) {
			if (display.wheelStartX == null) {
				display.wheelStartX = scroll.scrollLeft; display.wheelStartY = scroll.scrollTop;
				display.wheelDX = dx; display.wheelDY = dy;
				setTimeout(function() {
					if (display.wheelStartX == null) return;
					var movedX = scroll.scrollLeft - display.wheelStartX;
					var movedY = scroll.scrollTop - display.wheelStartY;
					var sample = (movedY && display.wheelDY && movedY / display.wheelDY) ||
						(movedX && display.wheelDX && movedX / display.wheelDX);
					display.wheelStartX = display.wheelStartY = null;
					if (!sample) return;
					wheelPixelsPerUnit = (wheelPixelsPerUnit * wheelSamples + sample) / (wheelSamples + 1);
					++wheelSamples;
				}, 200);
			} else {
				display.wheelDX += dx; display.wheelDY += dy;
			}
		}
	}

	// KEY EVENTS

	// Run a handler that was bound to a key.
	function doHandleBinding(cm, bound, dropShift) {
		if (typeof bound == "string") {
			bound = commands[bound];
			if (!bound) return false;
		}
		// Ensure previous input has been read, so that the handler sees a
		// consistent view of the document
		if (cm.display.pollingFast && readInput(cm)) cm.display.pollingFast = false;
		var prevShift = cm.display.shift, done = false;
		try {
			if (isReadOnly(cm)) cm.state.suppressEdits = true;
			if (dropShift) cm.display.shift = false;
			done = bound(cm) != Pass;
		} finally {
			cm.display.shift = prevShift;
			cm.state.suppressEdits = false;
		}
		return done;
	}

	// Collect the currently active keymaps.
	function allKeyMaps(cm) {
		var maps = cm.state.keyMaps.slice(0);
		if (cm.options.extraKeys) maps.push(cm.options.extraKeys);
		maps.push(cm.options.keyMap);
		return maps;
	}

	var maybeTransition;
	// Handle a key from the keydown event.
	function handleKeyBinding(cm, e) {
		// Handle automatic keymap transitions
		var startMap = getKeyMap(cm.options.keyMap), next = startMap.auto;
		clearTimeout(maybeTransition);
		if (next && !isModifierKey(e)) maybeTransition = setTimeout(function() {
			if (getKeyMap(cm.options.keyMap) == startMap) {
				cm.options.keyMap = (next.call ? next.call(null, cm) : next);
				keyMapChanged(cm);
			}
		}, 50);

		var name = keyName(e, true), handled = false;
		if (!name) return false;
		var keymaps = allKeyMaps(cm);

		if (e.shiftKey) {
			// First try to resolve full name (including 'Shift-'). Failing
			// that, see if there is a cursor-motion command (starting with
			// 'go') bound to the keyname without 'Shift-'.
			handled = lookupKey("Shift-" + name, keymaps, function(b) {return doHandleBinding(cm, b, true);})
				|| lookupKey(name, keymaps, function(b) {
					if (typeof b == "string" ? /^go[A-Z]/.test(b) : b.motion)
						return doHandleBinding(cm, b);
				});
		} else {
			handled = lookupKey(name, keymaps, function(b) { return doHandleBinding(cm, b); });
		}

		if (handled) {
			e_preventDefault(e);
			restartBlink(cm);
			signalLater(cm, "keyHandled", cm, name, e);
		}
		return handled;
	}

	// Handle a key from the keypress event
	function handleCharBinding(cm, e, ch) {
		var handled = lookupKey("'" + ch + "'", allKeyMaps(cm),
			function(b) { return doHandleBinding(cm, b, true); });
		if (handled) {
			e_preventDefault(e);
			restartBlink(cm);
			signalLater(cm, "keyHandled", cm, "'" + ch + "'", e);
		}
		return handled;
	}

	var lastStoppedKey = null;
	function onKeyDown(e) {
		var cm = this;
		ensureFocus(cm);
		if (signalDOMEvent(cm, e)) return;
		// IE does strange things with escape.
		if (ie && ie_version < 11 && e.keyCode == 27) e.returnValue = false;
		var code = e.keyCode;
		cm.display.shift = code == 16 || e.shiftKey;
		var handled = handleKeyBinding(cm, e);
		if (presto) {
			lastStoppedKey = handled ? code : null;
			// Opera has no cut event... we try to at least catch the key combo
			if (!handled && code == 88 && !hasCopyEvent && (mac ? e.metaKey : e.ctrlKey))
				cm.replaceSelection("", null, "cut");
		}

		// Turn mouse into crosshair when Alt is held on Mac.
		if (code == 18 && !/\bCodeMirror-crosshair\b/.test(cm.display.lineDiv.className))
			showCrossHair(cm);
	}

	function showCrossHair(cm) {
		var lineDiv = cm.display.lineDiv;
		addClass(lineDiv, "CodeMirror-crosshair");

		function up(e) {
			if (e.keyCode == 18 || !e.altKey) {
				rmClass(lineDiv, "CodeMirror-crosshair");
				off(document, "keyup", up);
				off(document, "mouseover", up);
			}
		}
		on(document, "keyup", up);
		on(document, "mouseover", up);
	}

	function onKeyUp(e) {
		if (signalDOMEvent(this, e)) return;
		if (e.keyCode == 16) this.doc.sel.shift = false;
	}

	function onKeyPress(e) {
		var cm = this;
		if (signalDOMEvent(cm, e) || e.ctrlKey || mac && e.metaKey) return;
		var keyCode = e.keyCode, charCode = e.charCode;
		if (presto && keyCode == lastStoppedKey) {lastStoppedKey = null; e_preventDefault(e); return;}
		if (((presto && (!e.which || e.which < 10)) || khtml) && handleKeyBinding(cm, e)) return;
		var ch = String.fromCharCode(charCode == null ? keyCode : charCode);
		if (handleCharBinding(cm, e, ch)) return;
		if (ie && ie_version >= 9) cm.display.inputHasSelection = null;
		fastPoll(cm);
	}

	// FOCUS/BLUR EVENTS

	function onFocus(cm) {
		if (cm.options.readOnly == "nocursor") return;
		if (!cm.state.focused) {
			signal(cm, "focus", cm);
			cm.state.focused = true;
			addClass(cm.display.wrapper, "CodeMirror-focused");
			// The prevInput test prevents this from firing when a context
			// menu is closed (since the resetInput would kill the
			// select-all detection hack)
			if (!cm.curOp && cm.display.selForContextMenu != cm.doc.sel) {
				resetInput(cm);
				if (webkit) setTimeout(bind(resetInput, cm, true), 0); // Issue #1730
			}
		}
		slowPoll(cm);
		restartBlink(cm);
	}
	function onBlur(cm) {
		if (cm.state.focused) {
			signal(cm, "blur", cm);
			cm.state.focused = false;
			rmClass(cm.display.wrapper, "CodeMirror-focused");
		}
		clearInterval(cm.display.blinker);
		setTimeout(function() {if (!cm.state.focused) cm.display.shift = false;}, 150);
	}

	// CONTEXT MENU HANDLING

	// To make the context menu work, we need to briefly unhide the
	// textarea (making it as unobtrusive as possible) to let the
	// right-click take effect on it.
	function onContextMenu(cm, e) {
		if (signalDOMEvent(cm, e, "contextmenu")) return;
		var display = cm.display;
		if (eventInWidget(display, e) || contextMenuInGutter(cm, e)) return;

		var pos = posFromMouse(cm, e), scrollPos = display.scroller.scrollTop;
		if (!pos || presto) return; // Opera is difficult.

		// Reset the current text selection only if the click is done outside of the selection
		// and 'resetSelectionOnContextMenu' option is true.
		var reset = cm.options.resetSelectionOnContextMenu;
		if (reset && cm.doc.sel.contains(pos) == -1)
			operation(cm, setSelection)(cm.doc, simpleSelection(pos), sel_dontScroll);

		var oldCSS = display.input.style.cssText;
		display.inputDiv.style.position = "absolute";
		display.input.style.cssText = "position: fixed; width: 30px; height: 30px; top: " + (e.clientY - 5) +
			"px; left: " + (e.clientX - 5) + "px; z-index: 1000; background: " +
			(ie ? "rgba(255, 255, 255, .05)" : "transparent") +
			"; outline: none; border-width: 0; outline: none; overflow: hidden; opacity: .05; filter: alpha(opacity=5);";
		focusInput(cm);
		resetInput(cm);
		// Adds "Select all" to context menu in FF
		if (!cm.somethingSelected()) display.input.value = display.prevInput = " ";
		display.selForContextMenu = cm.doc.sel;
		clearTimeout(display.detectingSelectAll);

		// Select-all will be greyed out if there's nothing to select, so
		// this adds a zero-width space so that we can later check whether
		// it got selected.
		function prepareSelectAllHack() {
			if (display.input.selectionStart != null) {
				var selected = cm.somethingSelected();
				var extval = display.input.value = "\u200b" + (selected ? display.input.value : "");
				display.prevInput = selected ? "" : "\u200b";
				display.input.selectionStart = 1; display.input.selectionEnd = extval.length;
				// Re-set this, in case some other handler touched the
				// selection in the meantime.
				display.selForContextMenu = cm.doc.sel;
			}
		}
		function rehide() {
			display.inputDiv.style.position = "relative";
			display.input.style.cssText = oldCSS;
			if (ie && ie_version < 9) display.scrollbarV.scrollTop = display.scroller.scrollTop = scrollPos;
			slowPoll(cm);

			// Try to detect the user choosing select-all
			if (display.input.selectionStart != null) {
				if (!ie || (ie && ie_version < 9)) prepareSelectAllHack();
				var i = 0, poll = function() {
					if (display.selForContextMenu == cm.doc.sel && display.input.selectionStart == 0)
						operation(cm, commands.selectAll)(cm);
					else if (i++ < 10) display.detectingSelectAll = setTimeout(poll, 500);
					else resetInput(cm);
				};
				display.detectingSelectAll = setTimeout(poll, 200);
			}
		}

		if (ie && ie_version >= 9) prepareSelectAllHack();
		if (captureRightClick) {
			e_stop(e);
			var mouseup = function() {
				off(window, "mouseup", mouseup);
				setTimeout(rehide, 20);
			};
			on(window, "mouseup", mouseup);
		} else {
			setTimeout(rehide, 50);
		}
	}

	function contextMenuInGutter(cm, e) {
		if (!hasHandler(cm, "gutterContextMenu")) return false;
		return gutterEvent(cm, e, "gutterContextMenu", false, signal);
	}

	// UPDATING

	// Compute the position of the end of a change (its 'to' property
	// refers to the pre-change end).
	var changeEnd = CodeMirror.changeEnd = function(change) {
		if (!change.text) return change.to;
		return Pos(change.from.line + change.text.length - 1,
			lst(change.text).length + (change.text.length == 1 ? change.from.ch : 0));
	};

	// Adjust a position to refer to the post-change position of the
	// same text, or the end of the change if the change covers it.
	function adjustForChange(pos, change) {
		if (cmp(pos, change.from) < 0) return pos;
		if (cmp(pos, change.to) <= 0) return changeEnd(change);

		var line = pos.line + change.text.length - (change.to.line - change.from.line) - 1, ch = pos.ch;
		if (pos.line == change.to.line) ch += changeEnd(change).ch - change.to.ch;
		return Pos(line, ch);
	}

	function computeSelAfterChange(doc, change) {
		var out = [];
		for (var i = 0; i < doc.sel.ranges.length; i++) {
			var range = doc.sel.ranges[i];
			out.push(new Range(adjustForChange(range.anchor, change),
				adjustForChange(range.head, change)));
		}
		return normalizeSelection(out, doc.sel.primIndex);
	}

	function offsetPos(pos, old, nw) {
		if (pos.line == old.line)
			return Pos(nw.line, pos.ch - old.ch + nw.ch);
		else
			return Pos(nw.line + (pos.line - old.line), pos.ch);
	}

	// Used by replaceSelections to allow moving the selection to the
	// start or around the replaced test. Hint may be "start" or "around".
	function computeReplacedSel(doc, changes, hint) {
		var out = [];
		var oldPrev = Pos(doc.first, 0), newPrev = oldPrev;
		for (var i = 0; i < changes.length; i++) {
			var change = changes[i];
			var from = offsetPos(change.from, oldPrev, newPrev);
			var to = offsetPos(changeEnd(change), oldPrev, newPrev);
			oldPrev = change.to;
			newPrev = to;
			if (hint == "around") {
				var range = doc.sel.ranges[i], inv = cmp(range.head, range.anchor) < 0;
				out[i] = new Range(inv ? to : from, inv ? from : to);
			} else {
				out[i] = new Range(from, from);
			}
		}
		return new Selection(out, doc.sel.primIndex);
	}

	// Allow "beforeChange" event handlers to influence a change
	function filterChange(doc, change, update) {
		var obj = {
			canceled: false,
			from: change.from,
			to: change.to,
			text: change.text,
			origin: change.origin,
			cancel: function() { this.canceled = true; }
		};
		if (update) obj.update = function(from, to, text, origin) {
			if (from) this.from = clipPos(doc, from);
			if (to) this.to = clipPos(doc, to);
			if (text) this.text = text;
			if (origin !== undefined) this.origin = origin;
		};
		signal(doc, "beforeChange", doc, obj);
		if (doc.cm) signal(doc.cm, "beforeChange", doc.cm, obj);

		if (obj.canceled) return null;
		return {from: obj.from, to: obj.to, text: obj.text, origin: obj.origin};
	}

	// Apply a change to a document, and add it to the document's
	// history, and propagating it to all linked documents.
	function makeChange(doc, change, ignoreReadOnly) {
		if (doc.cm) {
			if (!doc.cm.curOp) return operation(doc.cm, makeChange)(doc, change, ignoreReadOnly);
			if (doc.cm.state.suppressEdits) return;
		}

		if (hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange")) {
			change = filterChange(doc, change, true);
			if (!change) return;
		}

		// Possibly split or suppress the update based on the presence
		// of read-only spans in its range.
		var split = sawReadOnlySpans && !ignoreReadOnly && removeReadOnlyRanges(doc, change.from, change.to);
		if (split) {
			for (var i = split.length - 1; i >= 0; --i)
				makeChangeInner(doc, {from: split[i].from, to: split[i].to, text: i ? [""] : change.text});
		} else {
			makeChangeInner(doc, change);
		}
	}

	function makeChangeInner(doc, change) {
		if (change.text.length == 1 && change.text[0] == "" && cmp(change.from, change.to) == 0) return;
		var selAfter = computeSelAfterChange(doc, change);
		addChangeToHistory(doc, change, selAfter, doc.cm ? doc.cm.curOp.id : NaN);

		makeChangeSingleDoc(doc, change, selAfter, stretchSpansOverChange(doc, change));
		var rebased = [];

		linkedDocs(doc, function(doc, sharedHist) {
			if (!sharedHist && indexOf(rebased, doc.history) == -1) {
				rebaseHist(doc.history, change);
				rebased.push(doc.history);
			}
			makeChangeSingleDoc(doc, change, null, stretchSpansOverChange(doc, change));
		});
	}

	// Revert a change stored in a document's history.
	function makeChangeFromHistory(doc, type, allowSelectionOnly) {
		if (doc.cm && doc.cm.state.suppressEdits) return;

		var hist = doc.history, event, selAfter = doc.sel;
		var source = type == "undo" ? hist.done : hist.undone, dest = type == "undo" ? hist.undone : hist.done;

		// Verify that there is a useable event (so that ctrl-z won't
		// needlessly clear selection events)
		for (var i = 0; i < source.length; i++) {
			event = source[i];
			if (allowSelectionOnly ? event.ranges && !event.equals(doc.sel) : !event.ranges)
				break;
		}
		if (i == source.length) return;
		hist.lastOrigin = hist.lastSelOrigin = null;

		for (;;) {
			event = source.pop();
			if (event.ranges) {
				pushSelectionToHistory(event, dest);
				if (allowSelectionOnly && !event.equals(doc.sel)) {
					setSelection(doc, event, {clearRedo: false});
					return;
				}
				selAfter = event;
			}
			else break;
		}

		// Build up a reverse change object to add to the opposite history
		// stack (redo when undoing, and vice versa).
		var antiChanges = [];
		pushSelectionToHistory(selAfter, dest);
		dest.push({changes: antiChanges, generation: hist.generation});
		hist.generation = event.generation || ++hist.maxGeneration;

		var filter = hasHandler(doc, "beforeChange") || doc.cm && hasHandler(doc.cm, "beforeChange");

		for (var i = event.changes.length - 1; i >= 0; --i) {
			var change = event.changes[i];
			change.origin = type;
			if (filter && !filterChange(doc, change, false)) {
				source.length = 0;
				return;
			}

			antiChanges.push(historyChangeFromChange(doc, change));

			var after = i ? computeSelAfterChange(doc, change, null) : lst(source);
			makeChangeSingleDoc(doc, change, after, mergeOldSpans(doc, change));
			if (!i && doc.cm) doc.cm.scrollIntoView(change);
			var rebased = [];

			// Propagate to the linked documents
			linkedDocs(doc, function(doc, sharedHist) {
				if (!sharedHist && indexOf(rebased, doc.history) == -1) {
					rebaseHist(doc.history, change);
					rebased.push(doc.history);
				}
				makeChangeSingleDoc(doc, change, null, mergeOldSpans(doc, change));
			});
		}
	}

	// Sub-views need their line numbers shifted when text is added
	// above or below them in the parent document.
	function shiftDoc(doc, distance) {
		if (distance == 0) return;
		doc.first += distance;
		doc.sel = new Selection(map(doc.sel.ranges, function(range) {
			return new Range(Pos(range.anchor.line + distance, range.anchor.ch),
				Pos(range.head.line + distance, range.head.ch));
		}), doc.sel.primIndex);
		if (doc.cm) {
			regChange(doc.cm, doc.first, doc.first - distance, distance);
			for (var d = doc.cm.display, l = d.viewFrom; l < d.viewTo; l++)
				regLineChange(doc.cm, l, "gutter");
		}
	}

	// More lower-level change function, handling only a single document
	// (not linked ones).
	function makeChangeSingleDoc(doc, change, selAfter, spans) {
		if (doc.cm && !doc.cm.curOp)
			return operation(doc.cm, makeChangeSingleDoc)(doc, change, selAfter, spans);

		if (change.to.line < doc.first) {
			shiftDoc(doc, change.text.length - 1 - (change.to.line - change.from.line));
			return;
		}
		if (change.from.line > doc.lastLine()) return;

		// Clip the change to the size of this doc
		if (change.from.line < doc.first) {
			var shift = change.text.length - 1 - (doc.first - change.from.line);
			shiftDoc(doc, shift);
			change = {from: Pos(doc.first, 0), to: Pos(change.to.line + shift, change.to.ch),
				text: [lst(change.text)], origin: change.origin};
		}
		var last = doc.lastLine();
		if (change.to.line > last) {
			change = {from: change.from, to: Pos(last, getLine(doc, last).text.length),
				text: [change.text[0]], origin: change.origin};
		}

		change.removed = getBetween(doc, change.from, change.to);

		if (!selAfter) selAfter = computeSelAfterChange(doc, change, null);
		if (doc.cm) makeChangeSingleDocInEditor(doc.cm, change, spans);
		else updateDoc(doc, change, spans);
		setSelectionNoUndo(doc, selAfter, sel_dontScroll);
	}

	// Handle the interaction of a change to a document with the editor
	// that this document is part of.
	function makeChangeSingleDocInEditor(cm, change, spans) {
		var doc = cm.doc, display = cm.display, from = change.from, to = change.to;

		var recomputeMaxLength = false, checkWidthStart = from.line;
		if (!cm.options.lineWrapping) {
			checkWidthStart = lineNo(visualLine(getLine(doc, from.line)));
			doc.iter(checkWidthStart, to.line + 1, function(line) {
				if (line == display.maxLine) {
					recomputeMaxLength = true;
					return true;
				}
			});
		}

		if (doc.sel.contains(change.from, change.to) > -1)
			signalCursorActivity(cm);

		updateDoc(doc, change, spans, estimateHeight(cm));

		if (!cm.options.lineWrapping) {
			doc.iter(checkWidthStart, from.line + change.text.length, function(line) {
				var len = lineLength(line);
				if (len > display.maxLineLength) {
					display.maxLine = line;
					display.maxLineLength = len;
					display.maxLineChanged = true;
					recomputeMaxLength = false;
				}
			});
			if (recomputeMaxLength) cm.curOp.updateMaxLine = true;
		}

		// Adjust frontier, schedule worker
		doc.frontier = Math.min(doc.frontier, from.line);
		startWorker(cm, 400);

		var lendiff = change.text.length - (to.line - from.line) - 1;
		// Remember that these lines changed, for updating the display
		if (from.line == to.line && change.text.length == 1 && !isWholeLineUpdate(cm.doc, change))
			regLineChange(cm, from.line, "text");
		else
			regChange(cm, from.line, to.line + 1, lendiff);

		var changesHandler = hasHandler(cm, "changes"), changeHandler = hasHandler(cm, "change");
		if (changeHandler || changesHandler) {
			var obj = {
				from: from, to: to,
				text: change.text,
				removed: change.removed,
				origin: change.origin
			};
			if (changeHandler) signalLater(cm, "change", cm, obj);
			if (changesHandler) (cm.curOp.changeObjs || (cm.curOp.changeObjs = [])).push(obj);
		}
		cm.display.selForContextMenu = null;
	}

	function replaceRange(doc, code, from, to, origin) {
		if (!to) to = from;
		if (cmp(to, from) < 0) { var tmp = to; to = from; from = tmp; }
		if (typeof code == "string") code = splitLines(code);
		makeChange(doc, {from: from, to: to, text: code, origin: origin});
	}

	// SCROLLING THINGS INTO VIEW

	// If an editor sits on the top or bottom of the window, partially
	// scrolled out of view, this ensures that the cursor is visible.
	function maybeScrollWindow(cm, coords) {
		var display = cm.display, box = display.sizer.getBoundingClientRect(), doScroll = null;
		if (coords.top + box.top < 0) doScroll = true;
		else if (coords.bottom + box.top > (window.innerHeight || document.documentElement.clientHeight)) doScroll = false;
		if (doScroll != null && !phantom) {
			var scrollNode = elt("div", "\u200b", null, "position: absolute; top: " +
				(coords.top - display.viewOffset - paddingTop(cm.display)) + "px; height: " +
				(coords.bottom - coords.top + scrollerCutOff) + "px; left: " +
				coords.left + "px; width: 2px;");
			cm.display.lineSpace.appendChild(scrollNode);
			scrollNode.scrollIntoView(doScroll);
			cm.display.lineSpace.removeChild(scrollNode);
		}
	}

	// Scroll a given position into view (immediately), verifying that
	// it actually became visible (as line heights are accurately
	// measured, the position of something may 'drift' during drawing).
	function scrollPosIntoView(cm, pos, end, margin) {
		if (margin == null) margin = 0;
		for (;;) {
			var changed = false, coords = cursorCoords(cm, pos);
			var endCoords = !end || end == pos ? coords : cursorCoords(cm, end);
			var scrollPos = calculateScrollPos(cm, Math.min(coords.left, endCoords.left),
				Math.min(coords.top, endCoords.top) - margin,
				Math.max(coords.left, endCoords.left),
				Math.max(coords.bottom, endCoords.bottom) + margin);
			var startTop = cm.doc.scrollTop, startLeft = cm.doc.scrollLeft;
			if (scrollPos.scrollTop != null) {
				setScrollTop(cm, scrollPos.scrollTop);
				if (Math.abs(cm.doc.scrollTop - startTop) > 1) changed = true;
			}
			if (scrollPos.scrollLeft != null) {
				setScrollLeft(cm, scrollPos.scrollLeft);
				if (Math.abs(cm.doc.scrollLeft - startLeft) > 1) changed = true;
			}
			if (!changed) return coords;
		}
	}

	// Scroll a given set of coordinates into view (immediately).
	function scrollIntoView(cm, x1, y1, x2, y2) {
		var scrollPos = calculateScrollPos(cm, x1, y1, x2, y2);
		if (scrollPos.scrollTop != null) setScrollTop(cm, scrollPos.scrollTop);
		if (scrollPos.scrollLeft != null) setScrollLeft(cm, scrollPos.scrollLeft);
	}

	// Calculate a new scroll position needed to scroll the given
	// rectangle into view. Returns an object with scrollTop and
	// scrollLeft properties. When these are undefined, the
	// vertical/horizontal position does not need to be adjusted.
	function calculateScrollPos(cm, x1, y1, x2, y2) {
		var display = cm.display, snapMargin = textHeight(cm.display);
		if (y1 < 0) y1 = 0;
		var screentop = cm.curOp && cm.curOp.scrollTop != null ? cm.curOp.scrollTop : display.scroller.scrollTop;
		var screen = display.scroller.clientHeight - scrollerCutOff, result = {};
		var docBottom = cm.doc.height + paddingVert(display);
		var atTop = y1 < snapMargin, atBottom = y2 > docBottom - snapMargin;
		if (y1 < screentop) {
			result.scrollTop = atTop ? 0 : y1;
		} else if (y2 > screentop + screen) {
			var newTop = Math.min(y1, (atBottom ? docBottom : y2) - screen);
			if (newTop != screentop) result.scrollTop = newTop;
		}

		var screenleft = cm.curOp && cm.curOp.scrollLeft != null ? cm.curOp.scrollLeft : display.scroller.scrollLeft;
		var screenw = display.scroller.clientWidth - scrollerCutOff;
		x1 += display.gutters.offsetWidth; x2 += display.gutters.offsetWidth;
		var gutterw = display.gutters.offsetWidth;
		var atLeft = x1 < gutterw + 10;
		if (x1 < screenleft + gutterw || atLeft) {
			if (atLeft) x1 = 0;
			result.scrollLeft = Math.max(0, x1 - 10 - gutterw);
		} else if (x2 > screenw + screenleft - 3) {
			result.scrollLeft = x2 + 10 - screenw;
		}
		return result;
	}

	// Store a relative adjustment to the scroll position in the current
	// operation (to be applied when the operation finishes).
	function addToScrollPos(cm, left, top) {
		if (left != null || top != null) resolveScrollToPos(cm);
		if (left != null)
			cm.curOp.scrollLeft = (cm.curOp.scrollLeft == null ? cm.doc.scrollLeft : cm.curOp.scrollLeft) + left;
		if (top != null)
			cm.curOp.scrollTop = (cm.curOp.scrollTop == null ? cm.doc.scrollTop : cm.curOp.scrollTop) + top;
	}

	// Make sure that at the end of the operation the current cursor is
	// shown.
	function ensureCursorVisible(cm) {
		resolveScrollToPos(cm);
		var cur = cm.getCursor(), from = cur, to = cur;
		if (!cm.options.lineWrapping) {
			from = cur.ch ? Pos(cur.line, cur.ch - 1) : cur;
			to = Pos(cur.line, cur.ch + 1);
		}
		cm.curOp.scrollToPos = {from: from, to: to, margin: cm.options.cursorScrollMargin, isCursor: true};
	}

	// When an operation has its scrollToPos property set, and another
	// scroll action is applied before the end of the operation, this
	// 'simulates' scrolling that position into view in a cheap way, so
	// that the effect of intermediate scroll commands is not ignored.
	function resolveScrollToPos(cm) {
		var range = cm.curOp.scrollToPos;
		if (range) {
			cm.curOp.scrollToPos = null;
			var from = estimateCoords(cm, range.from), to = estimateCoords(cm, range.to);
			var sPos = calculateScrollPos(cm, Math.min(from.left, to.left),
				Math.min(from.top, to.top) - range.margin,
				Math.max(from.right, to.right),
				Math.max(from.bottom, to.bottom) + range.margin);
			cm.scrollTo(sPos.scrollLeft, sPos.scrollTop);
		}
	}

	// API UTILITIES

	// Indent the given line. The how parameter can be "smart",
	// "add"/null, "subtract", or "prev". When aggressive is false
	// (typically set to true for forced single-line indents), empty
	// lines are not indented, and places where the mode returns Pass
	// are left alone.
	function indentLine(cm, n, how, aggressive) {
		var doc = cm.doc, state;
		if (how == null) how = "add";
		if (how == "smart") {
			// Fall back to "prev" when the mode doesn't have an indentation
			// method.
			if (!cm.doc.mode.indent) how = "prev";
			else state = getStateBefore(cm, n);
		}

		var tabSize = cm.options.tabSize;
		var line = getLine(doc, n), curSpace = countColumn(line.text, null, tabSize);
		if (line.stateAfter) line.stateAfter = null;
		var curSpaceString = line.text.match(/^\s*/)[0], indentation;
		if (!aggressive && !/\S/.test(line.text)) {
			indentation = 0;
			how = "not";
		} else if (how == "smart") {
			indentation = cm.doc.mode.indent(state, line.text.slice(curSpaceString.length), line.text);
			if (indentation == Pass) {
				if (!aggressive) return;
				how = "prev";
			}
		}
		if (how == "prev") {
			if (n > doc.first) indentation = countColumn(getLine(doc, n-1).text, null, tabSize);
			else indentation = 0;
		} else if (how == "add") {
			indentation = curSpace + cm.options.indentUnit;
		} else if (how == "subtract") {
			indentation = curSpace - cm.options.indentUnit;
		} else if (typeof how == "number") {
			indentation = curSpace + how;
		}
		indentation = Math.max(0, indentation);

		var indentString = "", pos = 0;
		if (cm.options.indentWithTabs)
			for (var i = Math.floor(indentation / tabSize); i; --i) {pos += tabSize; indentString += "\t";}
		if (pos < indentation) indentString += spaceStr(indentation - pos);

		if (indentString != curSpaceString) {
			replaceRange(cm.doc, indentString, Pos(n, 0), Pos(n, curSpaceString.length), "+input");
		} else {
			// Ensure that, if the cursor was in the whitespace at the start
			// of the line, it is moved to the end of that space.
			for (var i = 0; i < doc.sel.ranges.length; i++) {
				var range = doc.sel.ranges[i];
				if (range.head.line == n && range.head.ch < curSpaceString.length) {
					var pos = Pos(n, curSpaceString.length);
					replaceOneSelection(doc, i, new Range(pos, pos));
					break;
				}
			}
		}
		line.stateAfter = null;
	}

	// Utility for applying a change to a line by handle or number,
	// returning the number and optionally registering the line as
	// changed.
	function changeLine(doc, handle, changeType, op) {
		var no = handle, line = handle;
		if (typeof handle == "number") line = getLine(doc, clipLine(doc, handle));
		else no = lineNo(handle);
		if (no == null) return null;
		if (op(line, no) && doc.cm) regLineChange(doc.cm, no, changeType);
		return line;
	}

	// Helper for deleting text near the selection(s), used to implement
	// backspace, delete, and similar functionality.
	function deleteNearSelection(cm, compute) {
		var ranges = cm.doc.sel.ranges, kill = [];
		// Build up a set of ranges to kill first, merging overlapping
		// ranges.
		for (var i = 0; i < ranges.length; i++) {
			var toKill = compute(ranges[i]);
			while (kill.length && cmp(toKill.from, lst(kill).to) <= 0) {
				var replaced = kill.pop();
				if (cmp(replaced.from, toKill.from) < 0) {
					toKill.from = replaced.from;
					break;
				}
			}
			kill.push(toKill);
		}
		// Next, remove those actual ranges.
		runInOp(cm, function() {
			for (var i = kill.length - 1; i >= 0; i--)
				replaceRange(cm.doc, "", kill[i].from, kill[i].to, "+delete");
			ensureCursorVisible(cm);
		});
	}

	// Used for horizontal relative motion. Dir is -1 or 1 (left or
	// right), unit can be "char", "column" (like char, but doesn't
	// cross line boundaries), "word" (across next word), or "group" (to
	// the start of next group of word or non-word-non-whitespace
	// chars). The visually param controls whether, in right-to-left
	// text, direction 1 means to move towards the next index in the
	// string, or towards the character to the right of the current
	// position. The resulting position will have a hitSide=true
	// property if it reached the end of the document.
	function findPosH(doc, pos, dir, unit, visually) {
		var line = pos.line, ch = pos.ch, origDir = dir;
		var lineObj = getLine(doc, line);
		var possible = true;
		function findNextLine() {
			var l = line + dir;
			if (l < doc.first || l >= doc.first + doc.size) return (possible = false);
			line = l;
			return lineObj = getLine(doc, l);
		}
		function moveOnce(boundToLine) {
			var next = (visually ? moveVisually : moveLogically)(lineObj, ch, dir, true);
			if (next == null) {
				if (!boundToLine && findNextLine()) {
					if (visually) ch = (dir < 0 ? lineRight : lineLeft)(lineObj);
					else ch = dir < 0 ? lineObj.text.length : 0;
				} else return (possible = false);
			} else ch = next;
			return true;
		}

		if (unit == "char") moveOnce();
		else if (unit == "column") moveOnce(true);
		else if (unit == "word" || unit == "group") {
			var sawType = null, group = unit == "group";
			var helper = doc.cm && doc.cm.getHelper(pos, "wordChars");
			for (var first = true;; first = false) {
				if (dir < 0 && !moveOnce(!first)) break;
				var cur = lineObj.text.charAt(ch) || "\n";
				var type = isWordChar(cur, helper) ? "w"
					: group && cur == "\n" ? "n"
						: !group || /\s/.test(cur) ? null
							: "p";
				if (group && !first && !type) type = "s";
				if (sawType && sawType != type) {
					if (dir < 0) {dir = 1; moveOnce();}
					break;
				}

				if (type) sawType = type;
				if (dir > 0 && !moveOnce(!first)) break;
			}
		}
		var result = skipAtomic(doc, Pos(line, ch), origDir, true);
		if (!possible) result.hitSide = true;
		return result;
	}

	// For relative vertical movement. Dir may be -1 or 1. Unit can be
	// "page" or "line". The resulting position will have a hitSide=true
	// property if it reached the end of the document.
	function findPosV(cm, pos, dir, unit) {
		var doc = cm.doc, x = pos.left, y;
		if (unit == "page") {
			var pageSize = Math.min(cm.display.wrapper.clientHeight, window.innerHeight || document.documentElement.clientHeight);
			y = pos.top + dir * (pageSize - (dir < 0 ? 1.5 : .5) * textHeight(cm.display));
		} else if (unit == "line") {
			y = dir > 0 ? pos.bottom + 3 : pos.top - 3;
		}
		for (;;) {
			var target = coordsChar(cm, x, y);
			if (!target.outside) break;
			if (dir < 0 ? y <= 0 : y >= doc.height) { target.hitSide = true; break; }
			y += dir * 5;
		}
		return target;
	}

	// Find the word at the given position (as returned by coordsChar).
	function findWordAt(cm, pos) {
		var doc = cm.doc, line = getLine(doc, pos.line).text;
		var start = pos.ch, end = pos.ch;
		if (line) {
			var helper = cm.getHelper(pos, "wordChars");
			if ((pos.xRel < 0 || end == line.length) && start) --start; else ++end;
			var startChar = line.charAt(start);
			var check = isWordChar(startChar, helper)
				? function(ch) { return isWordChar(ch, helper); }
				: /\s/.test(startChar) ? function(ch) {return /\s/.test(ch);}
					: function(ch) {return !/\s/.test(ch) && !isWordChar(ch);};
			while (start > 0 && check(line.charAt(start - 1))) --start;
			while (end < line.length && check(line.charAt(end))) ++end;
		}
		return new Range(Pos(pos.line, start), Pos(pos.line, end));
	}

	// EDITOR METHODS

	// The publicly visible API. Note that methodOp(f) means
	// 'wrap f in an operation, performed on its `this` parameter'.

	// This is not the complete set of editor methods. Most of the
	// methods defined on the Doc type are also injected into
	// CodeMirror.prototype, for backwards compatibility and
	// convenience.

	CodeMirror.prototype = {
		constructor: CodeMirror,
		focus: function(){window.focus(); focusInput(this); fastPoll(this);},

		setOption: function(option, value) {
			var options = this.options, old = options[option];
			if (options[option] == value && option != "mode") return;
			options[option] = value;
			if (optionHandlers.hasOwnProperty(option))
				operation(this, optionHandlers[option])(this, value, old);
		},

		getOption: function(option) {return this.options[option];},
		getDoc: function() {return this.doc;},

		addKeyMap: function(map, bottom) {
			this.state.keyMaps[bottom ? "push" : "unshift"](map);
		},
		removeKeyMap: function(map) {
			var maps = this.state.keyMaps;
			for (var i = 0; i < maps.length; ++i)
				if (maps[i] == map || (typeof maps[i] != "string" && maps[i].name == map)) {
					maps.splice(i, 1);
					return true;
				}
		},

		addOverlay: methodOp(function(spec, options) {
			var mode = spec.token ? spec : CodeMirror.getMode(this.options, spec);
			if (mode.startState) throw new Error("Overlays may not be stateful.");
			this.state.overlays.push({mode: mode, modeSpec: spec, opaque: options && options.opaque});
			this.state.modeGen++;
			regChange(this);
		}),
		removeOverlay: methodOp(function(spec) {
			var overlays = this.state.overlays;
			for (var i = 0; i < overlays.length; ++i) {
				var cur = overlays[i].modeSpec;
				if (cur == spec || typeof spec == "string" && cur.name == spec) {
					overlays.splice(i, 1);
					this.state.modeGen++;
					regChange(this);
					return;
				}
			}
		}),

		indentLine: methodOp(function(n, dir, aggressive) {
			if (typeof dir != "string" && typeof dir != "number") {
				if (dir == null) dir = this.options.smartIndent ? "smart" : "prev";
				else dir = dir ? "add" : "subtract";
			}
			if (isLine(this.doc, n)) indentLine(this, n, dir, aggressive);
		}),
		indentSelection: methodOp(function(how) {
			var ranges = this.doc.sel.ranges, end = -1;
			for (var i = 0; i < ranges.length; i++) {
				var range = ranges[i];
				if (!range.empty()) {
					var start = Math.max(end, range.from().line);
					var to = range.to();
					end = Math.min(this.lastLine(), to.line - (to.ch ? 0 : 1)) + 1;
					for (var j = start; j < end; ++j)
						indentLine(this, j, how);
				} else if (range.head.line > end) {
					indentLine(this, range.head.line, how, true);
					end = range.head.line;
					if (i == this.doc.sel.primIndex) ensureCursorVisible(this);
				}
			}
		}),

		// Fetch the parser token for a given character. Useful for hacks
		// that want to inspect the mode state (say, for completion).
		getTokenAt: function(pos, precise) {
			var doc = this.doc;
			pos = clipPos(doc, pos);
			var state = getStateBefore(this, pos.line, precise), mode = this.doc.mode;
			var line = getLine(doc, pos.line);
			var stream = new StringStream(line.text, this.options.tabSize);
			while (stream.pos < pos.ch && !stream.eol()) {
				stream.start = stream.pos;
				var style = readToken(mode, stream, state);
			}
			return {start: stream.start,
				end: stream.pos,
				string: stream.current(),
				type: style || null,
				state: state};
		},

		getTokenTypeAt: function(pos) {
			pos = clipPos(this.doc, pos);
			var styles = getLineStyles(this, getLine(this.doc, pos.line));
			var before = 0, after = (styles.length - 1) / 2, ch = pos.ch;
			var type;
			if (ch == 0) type = styles[2];
			else for (;;) {
				var mid = (before + after) >> 1;
				if ((mid ? styles[mid * 2 - 1] : 0) >= ch) after = mid;
				else if (styles[mid * 2 + 1] < ch) before = mid + 1;
				else { type = styles[mid * 2 + 2]; break; }
			}
			var cut = type ? type.indexOf("cm-overlay ") : -1;
			return cut < 0 ? type : cut == 0 ? null : type.slice(0, cut - 1);
		},

		getModeAt: function(pos) {
			var mode = this.doc.mode;
			if (!mode.innerMode) return mode;
			return CodeMirror.innerMode(mode, this.getTokenAt(pos).state).mode;
		},

		getHelper: function(pos, type) {
			return this.getHelpers(pos, type)[0];
		},

		getHelpers: function(pos, type) {
			var found = [];
			if (!helpers.hasOwnProperty(type)) return helpers;
			var help = helpers[type], mode = this.getModeAt(pos);
			if (typeof mode[type] == "string") {
				if (help[mode[type]]) found.push(help[mode[type]]);
			} else if (mode[type]) {
				for (var i = 0; i < mode[type].length; i++) {
					var val = help[mode[type][i]];
					if (val) found.push(val);
				}
			} else if (mode.helperType && help[mode.helperType]) {
				found.push(help[mode.helperType]);
			} else if (help[mode.name]) {
				found.push(help[mode.name]);
			}
			for (var i = 0; i < help._global.length; i++) {
				var cur = help._global[i];
				if (cur.pred(mode, this) && indexOf(found, cur.val) == -1)
					found.push(cur.val);
			}
			return found;
		},

		getStateAfter: function(line, precise) {
			var doc = this.doc;
			line = clipLine(doc, line == null ? doc.first + doc.size - 1: line);
			return getStateBefore(this, line + 1, precise);
		},

		cursorCoords: function(start, mode) {
			var pos, range = this.doc.sel.primary();
			if (start == null) pos = range.head;
			else if (typeof start == "object") pos = clipPos(this.doc, start);
			else pos = start ? range.from() : range.to();
			return cursorCoords(this, pos, mode || "page");
		},

		charCoords: function(pos, mode) {
			return charCoords(this, clipPos(this.doc, pos), mode || "page");
		},

		coordsChar: function(coords, mode) {
			coords = fromCoordSystem(this, coords, mode || "page");
			return coordsChar(this, coords.left, coords.top);
		},

		lineAtHeight: function(height, mode) {
			height = fromCoordSystem(this, {top: height, left: 0}, mode || "page").top;
			return lineAtHeight(this.doc, height + this.display.viewOffset);
		},
		heightAtLine: function(line, mode) {
			var end = false, last = this.doc.first + this.doc.size - 1;
			if (line < this.doc.first) line = this.doc.first;
			else if (line > last) { line = last; end = true; }
			var lineObj = getLine(this.doc, line);
			return intoCoordSystem(this, lineObj, {top: 0, left: 0}, mode || "page").top +
				(end ? this.doc.height - heightAtLine(lineObj) : 0);
		},

		defaultTextHeight: function() { return textHeight(this.display); },
		defaultCharWidth: function() { return charWidth(this.display); },

		setGutterMarker: methodOp(function(line, gutterID, value) {
			return changeLine(this.doc, line, "gutter", function(line) {
				var markers = line.gutterMarkers || (line.gutterMarkers = {});
				markers[gutterID] = value;
				if (!value && isEmpty(markers)) line.gutterMarkers = null;
				return true;
			});
		}),

		clearGutter: methodOp(function(gutterID) {
			var cm = this, doc = cm.doc, i = doc.first;
			doc.iter(function(line) {
				if (line.gutterMarkers && line.gutterMarkers[gutterID]) {
					line.gutterMarkers[gutterID] = null;
					regLineChange(cm, i, "gutter");
					if (isEmpty(line.gutterMarkers)) line.gutterMarkers = null;
				}
				++i;
			});
		}),

		addLineWidget: methodOp(function(handle, node, options) {
			return addLineWidget(this, handle, node, options);
		}),

		removeLineWidget: function(widget) { widget.clear(); },

		lineInfo: function(line) {
			if (typeof line == "number") {
				if (!isLine(this.doc, line)) return null;
				var n = line;
				line = getLine(this.doc, line);
				if (!line) return null;
			} else {
				var n = lineNo(line);
				if (n == null) return null;
			}
			return {line: n, handle: line, text: line.text, gutterMarkers: line.gutterMarkers,
				textClass: line.textClass, bgClass: line.bgClass, wrapClass: line.wrapClass,
				widgets: line.widgets};
		},

		getViewport: function() { return {from: this.display.viewFrom, to: this.display.viewTo};},

		addWidget: function(pos, node, scroll, vert, horiz) {
			var display = this.display;
			pos = cursorCoords(this, clipPos(this.doc, pos));
			var top = pos.bottom, left = pos.left;
			node.style.position = "absolute";
			display.sizer.appendChild(node);
			if (vert == "over") {
				top = pos.top;
			} else if (vert == "above" || vert == "near") {
				var vspace = Math.max(display.wrapper.clientHeight, this.doc.height),
					hspace = Math.max(display.sizer.clientWidth, display.lineSpace.clientWidth);
				// Default to positioning above (if specified and possible); otherwise default to positioning below
				if ((vert == 'above' || pos.bottom + node.offsetHeight > vspace) && pos.top > node.offsetHeight)
					top = pos.top - node.offsetHeight;
				else if (pos.bottom + node.offsetHeight <= vspace)
					top = pos.bottom;
				if (left + node.offsetWidth > hspace)
					left = hspace - node.offsetWidth;
			}
			node.style.top = top + "px";
			node.style.left = node.style.right = "";
			if (horiz == "right") {
				left = display.sizer.clientWidth - node.offsetWidth;
				node.style.right = "0px";
			} else {
				if (horiz == "left") left = 0;
				else if (horiz == "middle") left = (display.sizer.clientWidth - node.offsetWidth) / 2;
				node.style.left = left + "px";
			}
			if (scroll)
				scrollIntoView(this, left, top, left + node.offsetWidth, top + node.offsetHeight);
		},

		triggerOnKeyDown: methodOp(onKeyDown),
		triggerOnKeyPress: methodOp(onKeyPress),
		triggerOnKeyUp: methodOp(onKeyUp),

		execCommand: function(cmd) {
			if (commands.hasOwnProperty(cmd))
				return commands[cmd](this);
		},

		findPosH: function(from, amount, unit, visually) {
			var dir = 1;
			if (amount < 0) { dir = -1; amount = -amount; }
			for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
				cur = findPosH(this.doc, cur, dir, unit, visually);
				if (cur.hitSide) break;
			}
			return cur;
		},

		moveH: methodOp(function(dir, unit) {
			var cm = this;
			cm.extendSelectionsBy(function(range) {
				if (cm.display.shift || cm.doc.extend || range.empty())
					return findPosH(cm.doc, range.head, dir, unit, cm.options.rtlMoveVisually);
				else
					return dir < 0 ? range.from() : range.to();
			}, sel_move);
		}),

		deleteH: methodOp(function(dir, unit) {
			var sel = this.doc.sel, doc = this.doc;
			if (sel.somethingSelected())
				doc.replaceSelection("", null, "+delete");
			else
				deleteNearSelection(this, function(range) {
					var other = findPosH(doc, range.head, dir, unit, false);
					return dir < 0 ? {from: other, to: range.head} : {from: range.head, to: other};
				});
		}),

		findPosV: function(from, amount, unit, goalColumn) {
			var dir = 1, x = goalColumn;
			if (amount < 0) { dir = -1; amount = -amount; }
			for (var i = 0, cur = clipPos(this.doc, from); i < amount; ++i) {
				var coords = cursorCoords(this, cur, "div");
				if (x == null) x = coords.left;
				else coords.left = x;
				cur = findPosV(this, coords, dir, unit);
				if (cur.hitSide) break;
			}
			return cur;
		},

		moveV: methodOp(function(dir, unit) {
			var cm = this, doc = this.doc, goals = [];
			var collapse = !cm.display.shift && !doc.extend && doc.sel.somethingSelected();
			doc.extendSelectionsBy(function(range) {
				if (collapse)
					return dir < 0 ? range.from() : range.to();
				var headPos = cursorCoords(cm, range.head, "div");
				if (range.goalColumn != null) headPos.left = range.goalColumn;
				goals.push(headPos.left);
				var pos = findPosV(cm, headPos, dir, unit);
				if (unit == "page" && range == doc.sel.primary())
					addToScrollPos(cm, null, charCoords(cm, pos, "div").top - headPos.top);
				return pos;
			}, sel_move);
			if (goals.length) for (var i = 0; i < doc.sel.ranges.length; i++)
				doc.sel.ranges[i].goalColumn = goals[i];
		}),

		toggleOverwrite: function(value) {
			if (value != null && value == this.state.overwrite) return;
			if (this.state.overwrite = !this.state.overwrite)
				addClass(this.display.cursorDiv, "CodeMirror-overwrite");
			else
				rmClass(this.display.cursorDiv, "CodeMirror-overwrite");

			signal(this, "overwriteToggle", this, this.state.overwrite);
		},
		hasFocus: function() { return activeElt() == this.display.input; },

		scrollTo: methodOp(function(x, y) {
			if (x != null || y != null) resolveScrollToPos(this);
			if (x != null) this.curOp.scrollLeft = x;
			if (y != null) this.curOp.scrollTop = y;
		}),
		getScrollInfo: function() {
			var scroller = this.display.scroller, co = scrollerCutOff;
			return {left: scroller.scrollLeft, top: scroller.scrollTop,
				height: scroller.scrollHeight - co, width: scroller.scrollWidth - co,
				clientHeight: scroller.clientHeight - co, clientWidth: scroller.clientWidth - co};
		},

		scrollIntoView: methodOp(function(range, margin) {
			if (range == null) {
				range = {from: this.doc.sel.primary().head, to: null};
				if (margin == null) margin = this.options.cursorScrollMargin;
			} else if (typeof range == "number") {
				range = {from: Pos(range, 0), to: null};
			} else if (range.from == null) {
				range = {from: range, to: null};
			}
			if (!range.to) range.to = range.from;
			range.margin = margin || 0;

			if (range.from.line != null) {
				resolveScrollToPos(this);
				this.curOp.scrollToPos = range;
			} else {
				var sPos = calculateScrollPos(this, Math.min(range.from.left, range.to.left),
					Math.min(range.from.top, range.to.top) - range.margin,
					Math.max(range.from.right, range.to.right),
					Math.max(range.from.bottom, range.to.bottom) + range.margin);
				this.scrollTo(sPos.scrollLeft, sPos.scrollTop);
			}
		}),

		setSize: methodOp(function(width, height) {
			var cm = this;
			function interpret(val) {
				return typeof val == "number" || /^\d+$/.test(String(val)) ? val + "px" : val;
			}
			if (width != null) cm.display.wrapper.style.width = interpret(width);
			if (height != null) cm.display.wrapper.style.height = interpret(height);
			if (cm.options.lineWrapping) clearLineMeasurementCache(this);
			var lineNo = cm.display.viewFrom;
			cm.doc.iter(lineNo, cm.display.viewTo, function(line) {
				if (line.widgets) for (var i = 0; i < line.widgets.length; i++)
					if (line.widgets[i].noHScroll) { regLineChange(cm, lineNo, "widget"); break; }
				++lineNo;
			});
			cm.curOp.forceUpdate = true;
			signal(cm, "refresh", this);
		}),

		operation: function(f){return runInOp(this, f);},

		refresh: methodOp(function() {
			var oldHeight = this.display.cachedTextHeight;
			regChange(this);
			this.curOp.forceUpdate = true;
			clearCaches(this);
			this.scrollTo(this.doc.scrollLeft, this.doc.scrollTop);
			updateGutterSpace(this);
			if (oldHeight == null || Math.abs(oldHeight - textHeight(this.display)) > .5)
				estimateLineHeights(this);
			signal(this, "refresh", this);
		}),

		swapDoc: methodOp(function(doc) {
			var old = this.doc;
			old.cm = null;
			attachDoc(this, doc);
			clearCaches(this);
			resetInput(this);
			this.scrollTo(doc.scrollLeft, doc.scrollTop);
			signalLater(this, "swapDoc", this, old);
			return old;
		}),

		getInputField: function(){return this.display.input;},
		getWrapperElement: function(){return this.display.wrapper;},
		getScrollerElement: function(){return this.display.scroller;},
		getGutterElement: function(){return this.display.gutters;}
	};
	eventMixin(CodeMirror);

	// OPTION DEFAULTS

	// The default configuration options.
	var defaults = CodeMirror.defaults = {};
	// Functions to run when options are changed.
	var optionHandlers = CodeMirror.optionHandlers = {};

	function option(name, deflt, handle, notOnInit) {
		CodeMirror.defaults[name] = deflt;
		if (handle) optionHandlers[name] =
			notOnInit ? function(cm, val, old) {if (old != Init) handle(cm, val, old);} : handle;
	}

	// Passed to option handlers when there is no old value.
	var Init = CodeMirror.Init = {toString: function(){return "CodeMirror.Init";}};

	// These two are, on init, called from the constructor because they
	// have to be initialized before the editor can start at all.
	option("value", "", function(cm, val) {
		cm.setValue(val);
	}, true);
	option("mode", null, function(cm, val) {
		cm.doc.modeOption = val;
		loadMode(cm);
	}, true);

	option("indentUnit", 2, loadMode, true);
	option("indentWithTabs", false);
	option("smartIndent", true);
	option("tabSize", 4, function(cm) {
		resetModeState(cm);
		clearCaches(cm);
		regChange(cm);
	}, true);
	option("specialChars", /[\t\u0000-\u0019\u00ad\u200b\u2028\u2029\ufeff]/g, function(cm, val) {
		cm.options.specialChars = new RegExp(val.source + (val.test("\t") ? "" : "|\t"), "g");
		cm.refresh();
	}, true);
	option("specialCharPlaceholder", defaultSpecialCharPlaceholder, function(cm) {cm.refresh();}, true);
	option("electricChars", true);
	option("rtlMoveVisually", !windows);
	option("wholeLineUpdateBefore", true);

	option("theme", "default", function(cm) {
		themeChanged(cm);
		guttersChanged(cm);
	}, true);
	option("keyMap", "default", keyMapChanged);
	option("extraKeys", null);

	option("lineWrapping", false, wrappingChanged, true);
	option("gutters", [], function(cm) {
		setGuttersForLineNumbers(cm.options);
		guttersChanged(cm);
	}, true);
	option("fixedGutter", true, function(cm, val) {
		cm.display.gutters.style.left = val ? compensateForHScroll(cm.display) + "px" : "0";
		cm.refresh();
	}, true);
	option("coverGutterNextToScrollbar", false, updateScrollbars, true);
	option("lineNumbers", false, function(cm) {
		setGuttersForLineNumbers(cm.options);
		guttersChanged(cm);
	}, true);
	option("firstLineNumber", 1, guttersChanged, true);
	option("lineNumberFormatter", function(integer) {return integer;}, guttersChanged, true);
	option("showCursorWhenSelecting", false, updateSelection, true);

	option("resetSelectionOnContextMenu", true);

	option("readOnly", false, function(cm, val) {
		if (val == "nocursor") {
			onBlur(cm);
			cm.display.input.blur();
			cm.display.disabled = true;
		} else {
			cm.display.disabled = false;
			if (!val) resetInput(cm);
		}
	});
	option("disableInput", false, function(cm, val) {if (!val) resetInput(cm);}, true);
	option("dragDrop", true);

	option("cursorBlinkRate", 530);
	option("cursorScrollMargin", 0);
	option("cursorHeight", 1, updateSelection, true);
	option("singleCursorHeightPerLine", true, updateSelection, true);
	option("workTime", 100);
	option("workDelay", 100);
	option("flattenSpans", true, resetModeState, true);
	option("addModeClass", false, resetModeState, true);
	option("pollInterval", 100);
	option("undoDepth", 200, function(cm, val){cm.doc.history.undoDepth = val;});
	option("historyEventDelay", 1250);
	option("viewportMargin", 10, function(cm){cm.refresh();}, true);
	option("maxHighlightLength", 10000, resetModeState, true);
	option("moveInputWithCursor", true, function(cm, val) {
		if (!val) cm.display.inputDiv.style.top = cm.display.inputDiv.style.left = 0;
	});

	option("tabindex", null, function(cm, val) {
		cm.display.input.tabIndex = val || "";
	});
	option("autofocus", null);

	// MODE DEFINITION AND QUERYING

	// Known modes, by name and by MIME
	var modes = CodeMirror.modes = {}, mimeModes = CodeMirror.mimeModes = {};

	// Extra arguments are stored as the mode's dependencies, which is
	// used by (legacy) mechanisms like loadmode.js to automatically
	// load a mode. (Preferred mechanism is the require/define calls.)
	CodeMirror.defineMode = function(name, mode) {
		if (!CodeMirror.defaults.mode && name != "null") CodeMirror.defaults.mode = name;
		if (arguments.length > 2) {
			mode.dependencies = [];
			for (var i = 2; i < arguments.length; ++i) mode.dependencies.push(arguments[i]);
		}
		modes[name] = mode;
	};

	CodeMirror.defineMIME = function(mime, spec) {
		mimeModes[mime] = spec;
	};

	// Given a MIME type, a {name, ...options} config object, or a name
	// string, return a mode config object.
	CodeMirror.resolveMode = function(spec) {
		if (typeof spec == "string" && mimeModes.hasOwnProperty(spec)) {
			spec = mimeModes[spec];
		} else if (spec && typeof spec.name == "string" && mimeModes.hasOwnProperty(spec.name)) {
			var found = mimeModes[spec.name];
			if (typeof found == "string") found = {name: found};
			spec = createObj(found, spec);
			spec.name = found.name;
		} else if (typeof spec == "string" && /^[\w\-]+\/[\w\-]+\+xml$/.test(spec)) {
			return CodeMirror.resolveMode("application/xml");
		}
		if (typeof spec == "string") return {name: spec};
		else return spec || {name: "null"};
	};

	// Given a mode spec (anything that resolveMode accepts), find and
	// initialize an actual mode object.
	CodeMirror.getMode = function(options, spec) {
		var spec = CodeMirror.resolveMode(spec);
		var mfactory = modes[spec.name];
		if (!mfactory) return CodeMirror.getMode(options, "text/plain");
		var modeObj = mfactory(options, spec);
		if (modeExtensions.hasOwnProperty(spec.name)) {
			var exts = modeExtensions[spec.name];
			for (var prop in exts) {
				if (!exts.hasOwnProperty(prop)) continue;
				if (modeObj.hasOwnProperty(prop)) modeObj["_" + prop] = modeObj[prop];
				modeObj[prop] = exts[prop];
			}
		}
		modeObj.name = spec.name;
		if (spec.helperType) modeObj.helperType = spec.helperType;
		if (spec.modeProps) for (var prop in spec.modeProps)
			modeObj[prop] = spec.modeProps[prop];

		return modeObj;
	};

	// Minimal default mode.
	CodeMirror.defineMode("null", function() {
		return {token: function(stream) {stream.skipToEnd();}};
	});
	CodeMirror.defineMIME("text/plain", "null");

	// This can be used to attach properties to mode objects from
	// outside the actual mode definition.
	var modeExtensions = CodeMirror.modeExtensions = {};
	CodeMirror.extendMode = function(mode, properties) {
		var exts = modeExtensions.hasOwnProperty(mode) ? modeExtensions[mode] : (modeExtensions[mode] = {});
		copyObj(properties, exts);
	};

	// EXTENSIONS

	CodeMirror.defineExtension = function(name, func) {
		CodeMirror.prototype[name] = func;
	};
	CodeMirror.defineDocExtension = function(name, func) {
		Doc.prototype[name] = func;
	};
	CodeMirror.defineOption = option;

	var initHooks = [];
	CodeMirror.defineInitHook = function(f) {initHooks.push(f);};

	var helpers = CodeMirror.helpers = {};
	CodeMirror.registerHelper = function(type, name, value) {
		if (!helpers.hasOwnProperty(type)) helpers[type] = CodeMirror[type] = {_global: []};
		helpers[type][name] = value;
	};
	CodeMirror.registerGlobalHelper = function(type, name, predicate, value) {
		CodeMirror.registerHelper(type, name, value);
		helpers[type]._global.push({pred: predicate, val: value});
	};

	// MODE STATE HANDLING

	// Utility functions for working with state. Exported because nested
	// modes need to do this for their inner modes.

	var copyState = CodeMirror.copyState = function(mode, state) {
		if (state === true) return state;
		if (mode.copyState) return mode.copyState(state);
		var nstate = {};
		for (var n in state) {
			var val = state[n];
			if (val instanceof Array) val = val.concat([]);
			nstate[n] = val;
		}
		return nstate;
	};

	var startState = CodeMirror.startState = function(mode, a1, a2) {
		return mode.startState ? mode.startState(a1, a2) : true;
	};

	// Given a mode and a state (for that mode), find the inner mode and
	// state at the position that the state refers to.
	CodeMirror.innerMode = function(mode, state) {
		while (mode.innerMode) {
			var info = mode.innerMode(state);
			if (!info || info.mode == mode) break;
			state = info.state;
			mode = info.mode;
		}
		return info || {mode: mode, state: state};
	};

	// STANDARD COMMANDS

	// Commands are parameter-less actions that can be performed on an
	// editor, mostly used for keybindings.
	var commands = CodeMirror.commands = {
		selectAll: function(cm) {cm.setSelection(Pos(cm.firstLine(), 0), Pos(cm.lastLine()), sel_dontScroll);},
		singleSelection: function(cm) {
			cm.setSelection(cm.getCursor("anchor"), cm.getCursor("head"), sel_dontScroll);
		},
		killLine: function(cm) {
			deleteNearSelection(cm, function(range) {
				if (range.empty()) {
					var len = getLine(cm.doc, range.head.line).text.length;
					if (range.head.ch == len && range.head.line < cm.lastLine())
						return {from: range.head, to: Pos(range.head.line + 1, 0)};
					else
						return {from: range.head, to: Pos(range.head.line, len)};
				} else {
					return {from: range.from(), to: range.to()};
				}
			});
		},
		deleteLine: function(cm) {
			deleteNearSelection(cm, function(range) {
				return {from: Pos(range.from().line, 0),
					to: clipPos(cm.doc, Pos(range.to().line + 1, 0))};
			});
		},
		delLineLeft: function(cm) {
			deleteNearSelection(cm, function(range) {
				return {from: Pos(range.from().line, 0), to: range.from()};
			});
		},
		undo: function(cm) {cm.undo();},
		redo: function(cm) {cm.redo();},
		undoSelection: function(cm) {cm.undoSelection();},
		redoSelection: function(cm) {cm.redoSelection();},
		goDocStart: function(cm) {cm.extendSelection(Pos(cm.firstLine(), 0));},
		goDocEnd: function(cm) {cm.extendSelection(Pos(cm.lastLine()));},
		goLineStart: function(cm) {
			cm.extendSelectionsBy(function(range) { return lineStart(cm, range.head.line); },
				{origin: "+move", bias: 1});
		},
		goLineStartSmart: function(cm) {
			cm.extendSelectionsBy(function(range) {
				var start = lineStart(cm, range.head.line);
				var line = cm.getLineHandle(start.line);
				var order = getOrder(line);
				if (!order || order[0].level == 0) {
					var firstNonWS = Math.max(0, line.text.search(/\S/));
					var inWS = range.head.line == start.line && range.head.ch <= firstNonWS && range.head.ch;
					return Pos(start.line, inWS ? 0 : firstNonWS);
				}
				return start;
			}, {origin: "+move", bias: 1});
		},
		goLineEnd: function(cm) {
			cm.extendSelectionsBy(function(range) { return lineEnd(cm, range.head.line); },
				{origin: "+move", bias: -1});
		},
		goLineRight: function(cm) {
			cm.extendSelectionsBy(function(range) {
				var top = cm.charCoords(range.head, "div").top + 5;
				return cm.coordsChar({left: cm.display.lineDiv.offsetWidth + 100, top: top}, "div");
			}, sel_move);
		},
		goLineLeft: function(cm) {
			cm.extendSelectionsBy(function(range) {
				var top = cm.charCoords(range.head, "div").top + 5;
				return cm.coordsChar({left: 0, top: top}, "div");
			}, sel_move);
		},
		goLineUp: function(cm) {cm.moveV(-1, "line");},
		goLineDown: function(cm) {cm.moveV(1, "line");},
		goPageUp: function(cm) {cm.moveV(-1, "page");},
		goPageDown: function(cm) {cm.moveV(1, "page");},
		goCharLeft: function(cm) {cm.moveH(-1, "char");},
		goCharRight: function(cm) {cm.moveH(1, "char");},
		goColumnLeft: function(cm) {cm.moveH(-1, "column");},
		goColumnRight: function(cm) {cm.moveH(1, "column");},
		goWordLeft: function(cm) {cm.moveH(-1, "word");},
		goGroupRight: function(cm) {cm.moveH(1, "group");},
		goGroupLeft: function(cm) {cm.moveH(-1, "group");},
		goWordRight: function(cm) {cm.moveH(1, "word");},
		delCharBefore: function(cm) {cm.deleteH(-1, "char");},
		delCharAfter: function(cm) {cm.deleteH(1, "char");},
		delWordBefore: function(cm) {cm.deleteH(-1, "word");},
		delWordAfter: function(cm) {cm.deleteH(1, "word");},
		delGroupBefore: function(cm) {cm.deleteH(-1, "group");},
		delGroupAfter: function(cm) {cm.deleteH(1, "group");},
		indentAuto: function(cm) {cm.indentSelection("smart");},
		indentMore: function(cm) {cm.indentSelection("add");},
		indentLess: function(cm) {cm.indentSelection("subtract");},
		insertTab: function(cm) {cm.replaceSelection("\t");},
		insertSoftTab: function(cm) {
			var spaces = [], ranges = cm.listSelections(), tabSize = cm.options.tabSize;
			for (var i = 0; i < ranges.length; i++) {
				var pos = ranges[i].from();
				var col = countColumn(cm.getLine(pos.line), pos.ch, tabSize);
				spaces.push(new Array(tabSize - col % tabSize + 1).join(" "));
			}
			cm.replaceSelections(spaces);
		},
		defaultTab: function(cm) {
			if (cm.somethingSelected()) cm.indentSelection("add");
			else cm.execCommand("insertTab");
		},
		transposeChars: function(cm) {
			runInOp(cm, function() {
				var ranges = cm.listSelections(), newSel = [];
				for (var i = 0; i < ranges.length; i++) {
					var cur = ranges[i].head, line = getLine(cm.doc, cur.line).text;
					if (line) {
						if (cur.ch == line.length) cur = new Pos(cur.line, cur.ch - 1);
						if (cur.ch > 0) {
							cur = new Pos(cur.line, cur.ch + 1);
							cm.replaceRange(line.charAt(cur.ch - 1) + line.charAt(cur.ch - 2),
								Pos(cur.line, cur.ch - 2), cur, "+transpose");
						} else if (cur.line > cm.doc.first) {
							var prev = getLine(cm.doc, cur.line - 1).text;
							if (prev)
								cm.replaceRange(line.charAt(0) + "\n" + prev.charAt(prev.length - 1),
									Pos(cur.line - 1, prev.length - 1), Pos(cur.line, 1), "+transpose");
						}
					}
					newSel.push(new Range(cur, cur));
				}
				cm.setSelections(newSel);
			});
		},
		newlineAndIndent: function(cm) {
			runInOp(cm, function() {
				var len = cm.listSelections().length;
				for (var i = 0; i < len; i++) {
					var range = cm.listSelections()[i];
					cm.replaceRange("\n", range.anchor, range.head, "+input");
					cm.indentLine(range.from().line + 1, null, true);
					ensureCursorVisible(cm);
				}
			});
		},
		toggleOverwrite: function(cm) {cm.toggleOverwrite();}
	};

	// STANDARD KEYMAPS

	var keyMap = CodeMirror.keyMap = {};
	keyMap.basic = {
		"Left": "goCharLeft", "Right": "goCharRight", "Up": "goLineUp", "Down": "goLineDown",
		"End": "goLineEnd", "Home": "goLineStartSmart", "PageUp": "goPageUp", "PageDown": "goPageDown",
		"Delete": "delCharAfter", "Backspace": "delCharBefore", "Shift-Backspace": "delCharBefore",
		"Tab": "defaultTab", "Shift-Tab": "indentAuto",
		"Enter": "newlineAndIndent", "Insert": "toggleOverwrite",
		"Esc": "singleSelection"
	};
	// Note that the save and find-related commands aren't defined by
	// default. User code or addons can define them. Unknown commands
	// are simply ignored.
	keyMap.pcDefault = {
		"Ctrl-A": "selectAll", "Ctrl-D": "deleteLine", "Ctrl-Z": "undo", "Shift-Ctrl-Z": "redo", "Ctrl-Y": "redo",
		"Ctrl-Home": "goDocStart", "Ctrl-Up": "goDocStart", "Ctrl-End": "goDocEnd", "Ctrl-Down": "goDocEnd",
		"Ctrl-Left": "goGroupLeft", "Ctrl-Right": "goGroupRight", "Alt-Left": "goLineStart", "Alt-Right": "goLineEnd",
		"Ctrl-Backspace": "delGroupBefore", "Ctrl-Delete": "delGroupAfter", "Ctrl-S": "save", "Ctrl-F": "find",
		"Ctrl-G": "findNext", "Shift-Ctrl-G": "findPrev", "Shift-Ctrl-F": "replace", "Shift-Ctrl-R": "replaceAll",
		"Ctrl-[": "indentLess", "Ctrl-]": "indentMore",
		"Ctrl-U": "undoSelection", "Shift-Ctrl-U": "redoSelection", "Alt-U": "redoSelection",
		fallthrough: "basic"
	};
	keyMap.macDefault = {
		"Cmd-A": "selectAll", "Cmd-D": "deleteLine", "Cmd-Z": "undo", "Shift-Cmd-Z": "redo", "Cmd-Y": "redo",
		"Cmd-Up": "goDocStart", "Cmd-End": "goDocEnd", "Cmd-Down": "goDocEnd", "Alt-Left": "goGroupLeft",
		"Alt-Right": "goGroupRight", "Cmd-Left": "goLineStart", "Cmd-Right": "goLineEnd", "Alt-Backspace": "delGroupBefore",
		"Ctrl-Alt-Backspace": "delGroupAfter", "Alt-Delete": "delGroupAfter", "Cmd-S": "save", "Cmd-F": "find",
		"Cmd-G": "findNext", "Shift-Cmd-G": "findPrev", "Cmd-Alt-F": "replace", "Shift-Cmd-Alt-F": "replaceAll",
		"Cmd-[": "indentLess", "Cmd-]": "indentMore", "Cmd-Backspace": "delLineLeft",
		"Cmd-U": "undoSelection", "Shift-Cmd-U": "redoSelection",
		fallthrough: ["basic", "emacsy"]
	};
	// Very basic readline/emacs-style bindings, which are standard on Mac.
	keyMap.emacsy = {
		"Ctrl-F": "goCharRight", "Ctrl-B": "goCharLeft", "Ctrl-P": "goLineUp", "Ctrl-N": "goLineDown",
		"Alt-F": "goWordRight", "Alt-B": "goWordLeft", "Ctrl-A": "goLineStart", "Ctrl-E": "goLineEnd",
		"Ctrl-V": "goPageDown", "Shift-Ctrl-V": "goPageUp", "Ctrl-D": "delCharAfter", "Ctrl-H": "delCharBefore",
		"Alt-D": "delWordAfter", "Alt-Backspace": "delWordBefore", "Ctrl-K": "killLine", "Ctrl-T": "transposeChars"
	};
	keyMap["default"] = mac ? keyMap.macDefault : keyMap.pcDefault;

	// KEYMAP DISPATCH

	function getKeyMap(val) {
		if (typeof val == "string") return keyMap[val];
		else return val;
	}

	// Given an array of keymaps and a key name, call handle on any
	// bindings found, until that returns a truthy value, at which point
	// we consider the key handled. Implements things like binding a key
	// to false stopping further handling and keymap fallthrough.
	var lookupKey = CodeMirror.lookupKey = function(name, maps, handle) {
		function lookup(map) {
			map = getKeyMap(map);
			var found = map[name];
			if (found === false) return "stop";
			if (found != null && handle(found)) return true;
			if (map.nofallthrough) return "stop";

			var fallthrough = map.fallthrough;
			if (fallthrough == null) return false;
			if (Object.prototype.toString.call(fallthrough) != "[object Array]")
				return lookup(fallthrough);
			for (var i = 0; i < fallthrough.length; ++i) {
				var done = lookup(fallthrough[i]);
				if (done) return done;
			}
			return false;
		}

		for (var i = 0; i < maps.length; ++i) {
			var done = lookup(maps[i]);
			if (done) return done != "stop";
		}
	};

	// Modifier key presses don't count as 'real' key presses for the
	// purpose of keymap fallthrough.
	var isModifierKey = CodeMirror.isModifierKey = function(event) {
		var name = keyNames[event.keyCode];
		return name == "Ctrl" || name == "Alt" || name == "Shift" || name == "Mod";
	};

	// Look up the name of a key as indicated by an event object.
	var keyName = CodeMirror.keyName = function(event, noShift) {
		if (presto && event.keyCode == 34 && event["char"]) return false;
		var name = keyNames[event.keyCode];
		if (name == null || event.altGraphKey) return false;
		if (event.altKey) name = "Alt-" + name;
		if (flipCtrlCmd ? event.metaKey : event.ctrlKey) name = "Ctrl-" + name;
		if (flipCtrlCmd ? event.ctrlKey : event.metaKey) name = "Cmd-" + name;
		if (!noShift && event.shiftKey) name = "Shift-" + name;
		return name;
	};

	// FROMTEXTAREA

	CodeMirror.fromTextArea = function(textarea, options) {
		if (!options) options = {};
		options.value = textarea.value;
		if (!options.tabindex && textarea.tabindex)
			options.tabindex = textarea.tabindex;
		if (!options.placeholder && textarea.placeholder)
			options.placeholder = textarea.placeholder;
		// Set autofocus to true if this textarea is focused, or if it has
		// autofocus and no other element is focused.
		if (options.autofocus == null) {
			var hasFocus = activeElt();
			options.autofocus = hasFocus == textarea ||
				textarea.getAttribute("autofocus") != null && hasFocus == document.body;
		}

		function save() {textarea.value = cm.getValue();}
		if (textarea.form) {
			on(textarea.form, "submit", save);
			// Deplorable hack to make the submit method do the right thing.
			if (!options.leaveSubmitMethodAlone) {
				var form = textarea.form, realSubmit = form.submit;
				try {
					var wrappedSubmit = form.submit = function() {
						save();
						form.submit = realSubmit;
						form.submit();
						form.submit = wrappedSubmit;
					};
				} catch(e) {}
			}
		}

		textarea.style.display = "none";
		var cm = CodeMirror(function(node) {
			textarea.parentNode.insertBefore(node, textarea.nextSibling);
		}, options);
		cm.save = save;
		cm.getTextArea = function() { return textarea; };
		cm.toTextArea = function() {
			save();
			textarea.parentNode.removeChild(cm.getWrapperElement());
			textarea.style.display = "";
			if (textarea.form) {
				off(textarea.form, "submit", save);
				if (typeof textarea.form.submit == "function")
					textarea.form.submit = realSubmit;
			}
		};
		return cm;
	};

	// STRING STREAM

	// Fed to the mode parsers, provides helper functions to make
	// parsers more succinct.

	var StringStream = CodeMirror.StringStream = function(string, tabSize) {
		this.pos = this.start = 0;
		this.string = string;
		this.tabSize = tabSize || 8;
		this.lastColumnPos = this.lastColumnValue = 0;
		this.lineStart = 0;
	};

	StringStream.prototype = {
		eol: function() {return this.pos >= this.string.length;},
		sol: function() {return this.pos == this.lineStart;},
		peek: function() {return this.string.charAt(this.pos) || undefined;},
		next: function() {
			if (this.pos < this.string.length)
				return this.string.charAt(this.pos++);
		},
		eat: function(match) {
			var ch = this.string.charAt(this.pos);
			if (typeof match == "string") var ok = ch == match;
			else var ok = ch && (match.test ? match.test(ch) : match(ch));
			if (ok) {++this.pos; return ch;}
		},
		eatWhile: function(match) {
			var start = this.pos;
			while (this.eat(match)){}
			return this.pos > start;
		},
		eatSpace: function() {
			var start = this.pos;
			while (/[\s\u00a0]/.test(this.string.charAt(this.pos))) ++this.pos;
			return this.pos > start;
		},
		skipToEnd: function() {this.pos = this.string.length;},
		skipTo: function(ch) {
			var found = this.string.indexOf(ch, this.pos);
			if (found > -1) {this.pos = found; return true;}
		},
		backUp: function(n) {this.pos -= n;},
		column: function() {
			if (this.lastColumnPos < this.start) {
				this.lastColumnValue = countColumn(this.string, this.start, this.tabSize, this.lastColumnPos, this.lastColumnValue);
				this.lastColumnPos = this.start;
			}
			return this.lastColumnValue - (this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
		},
		indentation: function() {
			return countColumn(this.string, null, this.tabSize) -
				(this.lineStart ? countColumn(this.string, this.lineStart, this.tabSize) : 0);
		},
		match: function(pattern, consume, caseInsensitive) {
			if (typeof pattern == "string") {
				var cased = function(str) {return caseInsensitive ? str.toLowerCase() : str;};
				var substr = this.string.substr(this.pos, pattern.length);
				if (cased(substr) == cased(pattern)) {
					if (consume !== false) this.pos += pattern.length;
					return true;
				}
			} else {
				var match = this.string.slice(this.pos).match(pattern);
				if (match && match.index > 0) return null;
				if (match && consume !== false) this.pos += match[0].length;
				return match;
			}
		},
		current: function(){return this.string.slice(this.start, this.pos);},
		hideFirstChars: function(n, inner) {
			this.lineStart += n;
			try { return inner(); }
			finally { this.lineStart -= n; }
		}
	};

	// TEXTMARKERS

	// Created with markText and setBookmark methods. A TextMarker is a
	// handle that can be used to clear or find a marked position in the
	// document. Line objects hold arrays (markedSpans) containing
	// {from, to, marker} object pointing to such marker objects, and
	// indicating that such a marker is present on that line. Multiple
	// lines may point to the same marker when it spans across lines.
	// The spans will have null for their from/to properties when the
	// marker continues beyond the start/end of the line. Markers have
	// links back to the lines they currently touch.

	var TextMarker = CodeMirror.TextMarker = function(doc, type) {
		this.lines = [];
		this.type = type;
		this.doc = doc;
	};
	eventMixin(TextMarker);

	// Clear the marker.
	TextMarker.prototype.clear = function() {
		if (this.explicitlyCleared) return;
		var cm = this.doc.cm, withOp = cm && !cm.curOp;
		if (withOp) startOperation(cm);
		if (hasHandler(this, "clear")) {
			var found = this.find();
			if (found) signalLater(this, "clear", found.from, found.to);
		}
		var min = null, max = null;
		for (var i = 0; i < this.lines.length; ++i) {
			var line = this.lines[i];
			var span = getMarkedSpanFor(line.markedSpans, this);
			if (cm && !this.collapsed) regLineChange(cm, lineNo(line), "text");
			else if (cm) {
				if (span.to != null) max = lineNo(line);
				if (span.from != null) min = lineNo(line);
			}
			line.markedSpans = removeMarkedSpan(line.markedSpans, span);
			if (span.from == null && this.collapsed && !lineIsHidden(this.doc, line) && cm)
				updateLineHeight(line, textHeight(cm.display));
		}
		if (cm && this.collapsed && !cm.options.lineWrapping) for (var i = 0; i < this.lines.length; ++i) {
			var visual = visualLine(this.lines[i]), len = lineLength(visual);
			if (len > cm.display.maxLineLength) {
				cm.display.maxLine = visual;
				cm.display.maxLineLength = len;
				cm.display.maxLineChanged = true;
			}
		}

		if (min != null && cm && this.collapsed) regChange(cm, min, max + 1);
		this.lines.length = 0;
		this.explicitlyCleared = true;
		if (this.atomic && this.doc.cantEdit) {
			this.doc.cantEdit = false;
			if (cm) reCheckSelection(cm.doc);
		}
		if (cm) signalLater(cm, "markerCleared", cm, this);
		if (withOp) endOperation(cm);
		if (this.parent) this.parent.clear();
	};

	// Find the position of the marker in the document. Returns a {from,
	// to} object by default. Side can be passed to get a specific side
	// -- 0 (both), -1 (left), or 1 (right). When lineObj is true, the
	// Pos objects returned contain a line object, rather than a line
	// number (used to prevent looking up the same line twice).
	TextMarker.prototype.find = function(side, lineObj) {
		if (side == null && this.type == "bookmark") side = 1;
		var from, to;
		for (var i = 0; i < this.lines.length; ++i) {
			var line = this.lines[i];
			var span = getMarkedSpanFor(line.markedSpans, this);
			if (span.from != null) {
				from = Pos(lineObj ? line : lineNo(line), span.from);
				if (side == -1) return from;
			}
			if (span.to != null) {
				to = Pos(lineObj ? line : lineNo(line), span.to);
				if (side == 1) return to;
			}
		}
		return from && {from: from, to: to};
	};

	// Signals that the marker's widget changed, and surrounding layout
	// should be recomputed.
	TextMarker.prototype.changed = function() {
		var pos = this.find(-1, true), widget = this, cm = this.doc.cm;
		if (!pos || !cm) return;
		runInOp(cm, function() {
			var line = pos.line, lineN = lineNo(pos.line);
			var view = findViewForLine(cm, lineN);
			if (view) {
				clearLineMeasurementCacheFor(view);
				cm.curOp.selectionChanged = cm.curOp.forceUpdate = true;
			}
			cm.curOp.updateMaxLine = true;
			if (!lineIsHidden(widget.doc, line) && widget.height != null) {
				var oldHeight = widget.height;
				widget.height = null;
				var dHeight = widgetHeight(widget) - oldHeight;
				if (dHeight)
					updateLineHeight(line, line.height + dHeight);
			}
		});
	};

	TextMarker.prototype.attachLine = function(line) {
		if (!this.lines.length && this.doc.cm) {
			var op = this.doc.cm.curOp;
			if (!op.maybeHiddenMarkers || indexOf(op.maybeHiddenMarkers, this) == -1)
				(op.maybeUnhiddenMarkers || (op.maybeUnhiddenMarkers = [])).push(this);
		}
		this.lines.push(line);
	};
	TextMarker.prototype.detachLine = function(line) {
		this.lines.splice(indexOf(this.lines, line), 1);
		if (!this.lines.length && this.doc.cm) {
			var op = this.doc.cm.curOp;
			(op.maybeHiddenMarkers || (op.maybeHiddenMarkers = [])).push(this);
		}
	};

	// Collapsed markers have unique ids, in order to be able to order
	// them, which is needed for uniquely determining an outer marker
	// when they overlap (they may nest, but not partially overlap).
	var nextMarkerId = 0;

	// Create a marker, wire it up to the right lines, and
	function markText(doc, from, to, options, type) {
		// Shared markers (across linked documents) are handled separately
		// (markTextShared will call out to this again, once per
		// document).
		if (options && options.shared) return markTextShared(doc, from, to, options, type);
		// Ensure we are in an operation.
		if (doc.cm && !doc.cm.curOp) return operation(doc.cm, markText)(doc, from, to, options, type);

		var marker = new TextMarker(doc, type), diff = cmp(from, to);
		if (options) copyObj(options, marker, false);
		// Don't connect empty markers unless clearWhenEmpty is false
		if (diff > 0 || diff == 0 && marker.clearWhenEmpty !== false)
			return marker;
		if (marker.replacedWith) {
			// Showing up as a widget implies collapsed (widget replaces text)
			marker.collapsed = true;
			marker.widgetNode = elt("span", [marker.replacedWith], "CodeMirror-widget");
			if (!options.handleMouseEvents) marker.widgetNode.ignoreEvents = true;
			if (options.insertLeft) marker.widgetNode.insertLeft = true;
		}
		if (marker.collapsed) {
			if (conflictingCollapsedRange(doc, from.line, from, to, marker) ||
				from.line != to.line && conflictingCollapsedRange(doc, to.line, from, to, marker))
				throw new Error("Inserting collapsed marker partially overlapping an existing one");
			sawCollapsedSpans = true;
		}

		if (marker.addToHistory)
			addChangeToHistory(doc, {from: from, to: to, origin: "markText"}, doc.sel, NaN);

		var curLine = from.line, cm = doc.cm, updateMaxLine;
		doc.iter(curLine, to.line + 1, function(line) {
			if (cm && marker.collapsed && !cm.options.lineWrapping && visualLine(line) == cm.display.maxLine)
				updateMaxLine = true;
			if (marker.collapsed && curLine != from.line) updateLineHeight(line, 0);
			addMarkedSpan(line, new MarkedSpan(marker,
				curLine == from.line ? from.ch : null,
				curLine == to.line ? to.ch : null));
			++curLine;
		});
		// lineIsHidden depends on the presence of the spans, so needs a second pass
		if (marker.collapsed) doc.iter(from.line, to.line + 1, function(line) {
			if (lineIsHidden(doc, line)) updateLineHeight(line, 0);
		});

		if (marker.clearOnEnter) on(marker, "beforeCursorEnter", function() { marker.clear(); });

		if (marker.readOnly) {
			sawReadOnlySpans = true;
			if (doc.history.done.length || doc.history.undone.length)
				doc.clearHistory();
		}
		if (marker.collapsed) {
			marker.id = ++nextMarkerId;
			marker.atomic = true;
		}
		if (cm) {
			// Sync editor state
			if (updateMaxLine) cm.curOp.updateMaxLine = true;
			if (marker.collapsed)
				regChange(cm, from.line, to.line + 1);
			else if (marker.className || marker.title || marker.startStyle || marker.endStyle)
				for (var i = from.line; i <= to.line; i++) regLineChange(cm, i, "text");
			if (marker.atomic) reCheckSelection(cm.doc);
			signalLater(cm, "markerAdded", cm, marker);
		}
		return marker;
	}

	// SHARED TEXTMARKERS

	// A shared marker spans multiple linked documents. It is
	// implemented as a meta-marker-object controlling multiple normal
	// markers.
	var SharedTextMarker = CodeMirror.SharedTextMarker = function(markers, primary) {
		this.markers = markers;
		this.primary = primary;
		for (var i = 0; i < markers.length; ++i)
			markers[i].parent = this;
	};
	eventMixin(SharedTextMarker);

	SharedTextMarker.prototype.clear = function() {
		if (this.explicitlyCleared) return;
		this.explicitlyCleared = true;
		for (var i = 0; i < this.markers.length; ++i)
			this.markers[i].clear();
		signalLater(this, "clear");
	};
	SharedTextMarker.prototype.find = function(side, lineObj) {
		return this.primary.find(side, lineObj);
	};

	function markTextShared(doc, from, to, options, type) {
		options = copyObj(options);
		options.shared = false;
		var markers = [markText(doc, from, to, options, type)], primary = markers[0];
		var widget = options.widgetNode;
		linkedDocs(doc, function(doc) {
			if (widget) options.widgetNode = widget.cloneNode(true);
			markers.push(markText(doc, clipPos(doc, from), clipPos(doc, to), options, type));
			for (var i = 0; i < doc.linked.length; ++i)
				if (doc.linked[i].isParent) return;
			primary = lst(markers);
		});
		return new SharedTextMarker(markers, primary);
	}

	function findSharedMarkers(doc) {
		return doc.findMarks(Pos(doc.first, 0), doc.clipPos(Pos(doc.lastLine())),
			function(m) { return m.parent; });
	}

	function copySharedMarkers(doc, markers) {
		for (var i = 0; i < markers.length; i++) {
			var marker = markers[i], pos = marker.find();
			var mFrom = doc.clipPos(pos.from), mTo = doc.clipPos(pos.to);
			if (cmp(mFrom, mTo)) {
				var subMark = markText(doc, mFrom, mTo, marker.primary, marker.primary.type);
				marker.markers.push(subMark);
				subMark.parent = marker;
			}
		}
	}

	function detachSharedMarkers(markers) {
		for (var i = 0; i < markers.length; i++) {
			var marker = markers[i], linked = [marker.primary.doc];;
			linkedDocs(marker.primary.doc, function(d) { linked.push(d); });
			for (var j = 0; j < marker.markers.length; j++) {
				var subMarker = marker.markers[j];
				if (indexOf(linked, subMarker.doc) == -1) {
					subMarker.parent = null;
					marker.markers.splice(j--, 1);
				}
			}
		}
	}

	// TEXTMARKER SPANS

	function MarkedSpan(marker, from, to) {
		this.marker = marker;
		this.from = from; this.to = to;
	}

	// Search an array of spans for a span matching the given marker.
	function getMarkedSpanFor(spans, marker) {
		if (spans) for (var i = 0; i < spans.length; ++i) {
			var span = spans[i];
			if (span.marker == marker) return span;
		}
	}
	// Remove a span from an array, returning undefined if no spans are
	// left (we don't store arrays for lines without spans).
	function removeMarkedSpan(spans, span) {
		for (var r, i = 0; i < spans.length; ++i)
			if (spans[i] != span) (r || (r = [])).push(spans[i]);
		return r;
	}
	// Add a span to a line.
	function addMarkedSpan(line, span) {
		line.markedSpans = line.markedSpans ? line.markedSpans.concat([span]) : [span];
		span.marker.attachLine(line);
	}

	// Used for the algorithm that adjusts markers for a change in the
	// document. These functions cut an array of spans at a given
	// character position, returning an array of remaining chunks (or
	// undefined if nothing remains).
	function markedSpansBefore(old, startCh, isInsert) {
		if (old) for (var i = 0, nw; i < old.length; ++i) {
			var span = old[i], marker = span.marker;
			var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= startCh : span.from < startCh);
			if (startsBefore || span.from == startCh && marker.type == "bookmark" && (!isInsert || !span.marker.insertLeft)) {
				var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= startCh : span.to > startCh);
				(nw || (nw = [])).push(new MarkedSpan(marker, span.from, endsAfter ? null : span.to));
			}
		}
		return nw;
	}
	function markedSpansAfter(old, endCh, isInsert) {
		if (old) for (var i = 0, nw; i < old.length; ++i) {
			var span = old[i], marker = span.marker;
			var endsAfter = span.to == null || (marker.inclusiveRight ? span.to >= endCh : span.to > endCh);
			if (endsAfter || span.from == endCh && marker.type == "bookmark" && (!isInsert || span.marker.insertLeft)) {
				var startsBefore = span.from == null || (marker.inclusiveLeft ? span.from <= endCh : span.from < endCh);
				(nw || (nw = [])).push(new MarkedSpan(marker, startsBefore ? null : span.from - endCh,
					span.to == null ? null : span.to - endCh));
			}
		}
		return nw;
	}

	// Given a change object, compute the new set of marker spans that
	// cover the line in which the change took place. Removes spans
	// entirely within the change, reconnects spans belonging to the
	// same marker that appear on both sides of the change, and cuts off
	// spans partially within the change. Returns an array of span
	// arrays with one element for each line in (after) the change.
	function stretchSpansOverChange(doc, change) {
		var oldFirst = isLine(doc, change.from.line) && getLine(doc, change.from.line).markedSpans;
		var oldLast = isLine(doc, change.to.line) && getLine(doc, change.to.line).markedSpans;
		if (!oldFirst && !oldLast) return null;

		var startCh = change.from.ch, endCh = change.to.ch, isInsert = cmp(change.from, change.to) == 0;
		// Get the spans that 'stick out' on both sides
		var first = markedSpansBefore(oldFirst, startCh, isInsert);
		var last = markedSpansAfter(oldLast, endCh, isInsert);

		// Next, merge those two ends
		var sameLine = change.text.length == 1, offset = lst(change.text).length + (sameLine ? startCh : 0);
		if (first) {
			// Fix up .to properties of first
			for (var i = 0; i < first.length; ++i) {
				var span = first[i];
				if (span.to == null) {
					var found = getMarkedSpanFor(last, span.marker);
					if (!found) span.to = startCh;
					else if (sameLine) span.to = found.to == null ? null : found.to + offset;
				}
			}
		}
		if (last) {
			// Fix up .from in last (or move them into first in case of sameLine)
			for (var i = 0; i < last.length; ++i) {
				var span = last[i];
				if (span.to != null) span.to += offset;
				if (span.from == null) {
					var found = getMarkedSpanFor(first, span.marker);
					if (!found) {
						span.from = offset;
						if (sameLine) (first || (first = [])).push(span);
					}
				} else {
					span.from += offset;
					if (sameLine) (first || (first = [])).push(span);
				}
			}
		}
		// Make sure we didn't create any zero-length spans
		if (first) first = clearEmptySpans(first);
		if (last && last != first) last = clearEmptySpans(last);

		var newMarkers = [first];
		if (!sameLine) {
			// Fill gap with whole-line-spans
			var gap = change.text.length - 2, gapMarkers;
			if (gap > 0 && first)
				for (var i = 0; i < first.length; ++i)
					if (first[i].to == null)
						(gapMarkers || (gapMarkers = [])).push(new MarkedSpan(first[i].marker, null, null));
			for (var i = 0; i < gap; ++i)
				newMarkers.push(gapMarkers);
			newMarkers.push(last);
		}
		return newMarkers;
	}

	// Remove spans that are empty and don't have a clearWhenEmpty
	// option of false.
	function clearEmptySpans(spans) {
		for (var i = 0; i < spans.length; ++i) {
			var span = spans[i];
			if (span.from != null && span.from == span.to && span.marker.clearWhenEmpty !== false)
				spans.splice(i--, 1);
		}
		if (!spans.length) return null;
		return spans;
	}

	// Used for un/re-doing changes from the history. Combines the
	// result of computing the existing spans with the set of spans that
	// existed in the history (so that deleting around a span and then
	// undoing brings back the span).
	function mergeOldSpans(doc, change) {
		var old = getOldSpans(doc, change);
		var stretched = stretchSpansOverChange(doc, change);
		if (!old) return stretched;
		if (!stretched) return old;

		for (var i = 0; i < old.length; ++i) {
			var oldCur = old[i], stretchCur = stretched[i];
			if (oldCur && stretchCur) {
				spans: for (var j = 0; j < stretchCur.length; ++j) {
					var span = stretchCur[j];
					for (var k = 0; k < oldCur.length; ++k)
						if (oldCur[k].marker == span.marker) continue spans;
					oldCur.push(span);
				}
			} else if (stretchCur) {
				old[i] = stretchCur;
			}
		}
		return old;
	}

	// Used to 'clip' out readOnly ranges when making a change.
	function removeReadOnlyRanges(doc, from, to) {
		var markers = null;
		doc.iter(from.line, to.line + 1, function(line) {
			if (line.markedSpans) for (var i = 0; i < line.markedSpans.length; ++i) {
				var mark = line.markedSpans[i].marker;
				if (mark.readOnly && (!markers || indexOf(markers, mark) == -1))
					(markers || (markers = [])).push(mark);
			}
		});
		if (!markers) return null;
		var parts = [{from: from, to: to}];
		for (var i = 0; i < markers.length; ++i) {
			var mk = markers[i], m = mk.find(0);
			for (var j = 0; j < parts.length; ++j) {
				var p = parts[j];
				if (cmp(p.to, m.from) < 0 || cmp(p.from, m.to) > 0) continue;
				var newParts = [j, 1], dfrom = cmp(p.from, m.from), dto = cmp(p.to, m.to);
				if (dfrom < 0 || !mk.inclusiveLeft && !dfrom)
					newParts.push({from: p.from, to: m.from});
				if (dto > 0 || !mk.inclusiveRight && !dto)
					newParts.push({from: m.to, to: p.to});
				parts.splice.apply(parts, newParts);
				j += newParts.length - 1;
			}
		}
		return parts;
	}

	// Connect or disconnect spans from a line.
	function detachMarkedSpans(line) {
		var spans = line.markedSpans;
		if (!spans) return;
		for (var i = 0; i < spans.length; ++i)
			spans[i].marker.detachLine(line);
		line.markedSpans = null;
	}
	function attachMarkedSpans(line, spans) {
		if (!spans) return;
		for (var i = 0; i < spans.length; ++i)
			spans[i].marker.attachLine(line);
		line.markedSpans = spans;
	}

	// Helpers used when computing which overlapping collapsed span
	// counts as the larger one.
	function extraLeft(marker) { return marker.inclusiveLeft ? -1 : 0; }
	function extraRight(marker) { return marker.inclusiveRight ? 1 : 0; }

	// Returns a number indicating which of two overlapping collapsed
	// spans is larger (and thus includes the other). Falls back to
	// comparing ids when the spans cover exactly the same range.
	function compareCollapsedMarkers(a, b) {
		var lenDiff = a.lines.length - b.lines.length;
		if (lenDiff != 0) return lenDiff;
		var aPos = a.find(), bPos = b.find();
		var fromCmp = cmp(aPos.from, bPos.from) || extraLeft(a) - extraLeft(b);
		if (fromCmp) return -fromCmp;
		var toCmp = cmp(aPos.to, bPos.to) || extraRight(a) - extraRight(b);
		if (toCmp) return toCmp;
		return b.id - a.id;
	}

	// Find out whether a line ends or starts in a collapsed span. If
	// so, return the marker for that span.
	function collapsedSpanAtSide(line, start) {
		var sps = sawCollapsedSpans && line.markedSpans, found;
		if (sps) for (var sp, i = 0; i < sps.length; ++i) {
			sp = sps[i];
			if (sp.marker.collapsed && (start ? sp.from : sp.to) == null &&
				(!found || compareCollapsedMarkers(found, sp.marker) < 0))
				found = sp.marker;
		}
		return found;
	}
	function collapsedSpanAtStart(line) { return collapsedSpanAtSide(line, true); }
	function collapsedSpanAtEnd(line) { return collapsedSpanAtSide(line, false); }

	// Test whether there exists a collapsed span that partially
	// overlaps (covers the start or end, but not both) of a new span.
	// Such overlap is not allowed.
	function conflictingCollapsedRange(doc, lineNo, from, to, marker) {
		var line = getLine(doc, lineNo);
		var sps = sawCollapsedSpans && line.markedSpans;
		if (sps) for (var i = 0; i < sps.length; ++i) {
			var sp = sps[i];
			if (!sp.marker.collapsed) continue;
			var found = sp.marker.find(0);
			var fromCmp = cmp(found.from, from) || extraLeft(sp.marker) - extraLeft(marker);
			var toCmp = cmp(found.to, to) || extraRight(sp.marker) - extraRight(marker);
			if (fromCmp >= 0 && toCmp <= 0 || fromCmp <= 0 && toCmp >= 0) continue;
			if (fromCmp <= 0 && (cmp(found.to, from) > 0 || (sp.marker.inclusiveRight && marker.inclusiveLeft)) ||
				fromCmp >= 0 && (cmp(found.from, to) < 0 || (sp.marker.inclusiveLeft && marker.inclusiveRight)))
				return true;
		}
	}

	// A visual line is a line as drawn on the screen. Folding, for
	// example, can cause multiple logical lines to appear on the same
	// visual line. This finds the start of the visual line that the
	// given line is part of (usually that is the line itself).
	function visualLine(line) {
		var merged;
		while (merged = collapsedSpanAtStart(line))
			line = merged.find(-1, true).line;
		return line;
	}

	// Returns an array of logical lines that continue the visual line
	// started by the argument, or undefined if there are no such lines.
	function visualLineContinued(line) {
		var merged, lines;
		while (merged = collapsedSpanAtEnd(line)) {
			line = merged.find(1, true).line;
			(lines || (lines = [])).push(line);
		}
		return lines;
	}

	// Get the line number of the start of the visual line that the
	// given line number is part of.
	function visualLineNo(doc, lineN) {
		var line = getLine(doc, lineN), vis = visualLine(line);
		if (line == vis) return lineN;
		return lineNo(vis);
	}
	// Get the line number of the start of the next visual line after
	// the given line.
	function visualLineEndNo(doc, lineN) {
		if (lineN > doc.lastLine()) return lineN;
		var line = getLine(doc, lineN), merged;
		if (!lineIsHidden(doc, line)) return lineN;
		while (merged = collapsedSpanAtEnd(line))
			line = merged.find(1, true).line;
		return lineNo(line) + 1;
	}

	// Compute whether a line is hidden. Lines count as hidden when they
	// are part of a visual line that starts with another line, or when
	// they are entirely covered by collapsed, non-widget span.
	function lineIsHidden(doc, line) {
		var sps = sawCollapsedSpans && line.markedSpans;
		if (sps) for (var sp, i = 0; i < sps.length; ++i) {
			sp = sps[i];
			if (!sp.marker.collapsed) continue;
			if (sp.from == null) return true;
			if (sp.marker.widgetNode) continue;
			if (sp.from == 0 && sp.marker.inclusiveLeft && lineIsHiddenInner(doc, line, sp))
				return true;
		}
	}
	function lineIsHiddenInner(doc, line, span) {
		if (span.to == null) {
			var end = span.marker.find(1, true);
			return lineIsHiddenInner(doc, end.line, getMarkedSpanFor(end.line.markedSpans, span.marker));
		}
		if (span.marker.inclusiveRight && span.to == line.text.length)
			return true;
		for (var sp, i = 0; i < line.markedSpans.length; ++i) {
			sp = line.markedSpans[i];
			if (sp.marker.collapsed && !sp.marker.widgetNode && sp.from == span.to &&
				(sp.to == null || sp.to != span.from) &&
				(sp.marker.inclusiveLeft || span.marker.inclusiveRight) &&
				lineIsHiddenInner(doc, line, sp)) return true;
		}
	}

	// LINE WIDGETS

	// Line widgets are block elements displayed above or below a line.

	var LineWidget = CodeMirror.LineWidget = function(cm, node, options) {
		if (options) for (var opt in options) if (options.hasOwnProperty(opt))
			this[opt] = options[opt];
		this.cm = cm;
		this.node = node;
	};
	eventMixin(LineWidget);

	function adjustScrollWhenAboveVisible(cm, line, diff) {
		if (heightAtLine(line) < ((cm.curOp && cm.curOp.scrollTop) || cm.doc.scrollTop))
			addToScrollPos(cm, null, diff);
	}

	LineWidget.prototype.clear = function() {
		var cm = this.cm, ws = this.line.widgets, line = this.line, no = lineNo(line);
		if (no == null || !ws) return;
		for (var i = 0; i < ws.length; ++i) if (ws[i] == this) ws.splice(i--, 1);
		if (!ws.length) line.widgets = null;
		var height = widgetHeight(this);
		runInOp(cm, function() {
			adjustScrollWhenAboveVisible(cm, line, -height);
			regLineChange(cm, no, "widget");
			updateLineHeight(line, Math.max(0, line.height - height));
		});
	};
	LineWidget.prototype.changed = function() {
		var oldH = this.height, cm = this.cm, line = this.line;
		this.height = null;
		var diff = widgetHeight(this) - oldH;
		if (!diff) return;
		runInOp(cm, function() {
			cm.curOp.forceUpdate = true;
			adjustScrollWhenAboveVisible(cm, line, diff);
			updateLineHeight(line, line.height + diff);
		});
	};

	function widgetHeight(widget) {
		if (widget.height != null) return widget.height;
		if (!contains(document.body, widget.node)) {
			var parentStyle = "position: relative;";
			if (widget.coverGutter)
				parentStyle += "margin-left: -" + widget.cm.getGutterElement().offsetWidth + "px;";
			removeChildrenAndAdd(widget.cm.display.measure, elt("div", [widget.node], null, parentStyle));
		}
		return widget.height = widget.node.offsetHeight;
	}

	function addLineWidget(cm, handle, node, options) {
		var widget = new LineWidget(cm, node, options);
		if (widget.noHScroll) cm.display.alignWidgets = true;
		changeLine(cm.doc, handle, "widget", function(line) {
			var widgets = line.widgets || (line.widgets = []);
			if (widget.insertAt == null) widgets.push(widget);
			else widgets.splice(Math.min(widgets.length - 1, Math.max(0, widget.insertAt)), 0, widget);
			widget.line = line;
			if (!lineIsHidden(cm.doc, line)) {
				var aboveVisible = heightAtLine(line) < cm.doc.scrollTop;
				updateLineHeight(line, line.height + widgetHeight(widget));
				if (aboveVisible) addToScrollPos(cm, null, widget.height);
				cm.curOp.forceUpdate = true;
			}
			return true;
		});
		return widget;
	}

	// LINE DATA STRUCTURE

	// Line objects. These hold state related to a line, including
	// highlighting info (the styles array).
	var Line = CodeMirror.Line = function(text, markedSpans, estimateHeight) {
		this.text = text;
		attachMarkedSpans(this, markedSpans);
		this.height = estimateHeight ? estimateHeight(this) : 1;
	};
	eventMixin(Line);
	Line.prototype.lineNo = function() { return lineNo(this); };

	// Change the content (text, markers) of a line. Automatically
	// invalidates cached information and tries to re-estimate the
	// line's height.
	function updateLine(line, text, markedSpans, estimateHeight) {
		line.text = text;
		if (line.stateAfter) line.stateAfter = null;
		if (line.styles) line.styles = null;
		if (line.order != null) line.order = null;
		detachMarkedSpans(line);
		attachMarkedSpans(line, markedSpans);
		var estHeight = estimateHeight ? estimateHeight(line) : 1;
		if (estHeight != line.height) updateLineHeight(line, estHeight);
	}

	// Detach a line from the document tree and its markers.
	function cleanUpLine(line) {
		line.parent = null;
		detachMarkedSpans(line);
	}

	function extractLineClasses(type, output) {
		if (type) for (;;) {
			var lineClass = type.match(/(?:^|\s+)line-(background-)?(\S+)/);
			if (!lineClass) break;
			type = type.slice(0, lineClass.index) + type.slice(lineClass.index + lineClass[0].length);
			var prop = lineClass[1] ? "bgClass" : "textClass";
			if (output[prop] == null)
				output[prop] = lineClass[2];
			else if (!(new RegExp("(?:^|\s)" + lineClass[2] + "(?:$|\s)")).test(output[prop]))
				output[prop] += " " + lineClass[2];
		}
		return type;
	}

	function callBlankLine(mode, state) {
		if (mode.blankLine) return mode.blankLine(state);
		if (!mode.innerMode) return;
		var inner = CodeMirror.innerMode(mode, state);
		if (inner.mode.blankLine) return inner.mode.blankLine(inner.state);
	}

	function readToken(mode, stream, state) {
		for (var i = 0; i < 10; i++) {
			var style = mode.token(stream, state);
			if (stream.pos > stream.start) return style;
		}
		throw new Error("Mode " + mode.name + " failed to advance stream.");
	}

	// Run the given mode's parser over a line, calling f for each token.
	function runMode(cm, text, mode, state, f, lineClasses, forceToEnd) {
		var flattenSpans = mode.flattenSpans;
		if (flattenSpans == null) flattenSpans = cm.options.flattenSpans;
		var curStart = 0, curStyle = null;
		var stream = new StringStream(text, cm.options.tabSize), style;
		if (text == "") extractLineClasses(callBlankLine(mode, state), lineClasses);
		while (!stream.eol()) {
			if (stream.pos > cm.options.maxHighlightLength) {
				flattenSpans = false;
				if (forceToEnd) processLine(cm, text, state, stream.pos);
				stream.pos = text.length;
				style = null;
			} else {
				style = extractLineClasses(readToken(mode, stream, state), lineClasses);
			}
			if (cm.options.addModeClass) {
				var mName = CodeMirror.innerMode(mode, state).mode.name;
				if (mName) style = "m-" + (style ? mName + " " + style : mName);
			}
			if (!flattenSpans || curStyle != style) {
				if (curStart < stream.start) f(stream.start, curStyle);
				curStart = stream.start; curStyle = style;
			}
			stream.start = stream.pos;
		}
		while (curStart < stream.pos) {
			// Webkit seems to refuse to render text nodes longer than 57444 characters
			var pos = Math.min(stream.pos, curStart + 50000);
			f(pos, curStyle);
			curStart = pos;
		}
	}

	// Compute a style array (an array starting with a mode generation
	// -- for invalidation -- followed by pairs of end positions and
	// style strings), which is used to highlight the tokens on the
	// line.
	function highlightLine(cm, line, state, forceToEnd) {
		// A styles array always starts with a number identifying the
		// mode/overlays that it is based on (for easy invalidation).
		var st = [cm.state.modeGen], lineClasses = {};
		// Compute the base array of styles
		runMode(cm, line.text, cm.doc.mode, state, function(end, style) {
			st.push(end, style);
		}, lineClasses, forceToEnd);

		// Run overlays, adjust style array.
		for (var o = 0; o < cm.state.overlays.length; ++o) {
			var overlay = cm.state.overlays[o], i = 1, at = 0;
			runMode(cm, line.text, overlay.mode, true, function(end, style) {
				var start = i;
				// Ensure there's a token end at the current position, and that i points at it
				while (at < end) {
					var i_end = st[i];
					if (i_end > end)
						st.splice(i, 1, end, st[i+1], i_end);
					i += 2;
					at = Math.min(end, i_end);
				}
				if (!style) return;
				if (overlay.opaque) {
					st.splice(start, i - start, end, "cm-overlay " + style);
					i = start + 2;
				} else {
					for (; start < i; start += 2) {
						var cur = st[start+1];
						st[start+1] = (cur ? cur + " " : "") + "cm-overlay " + style;
					}
				}
			}, lineClasses);
		}

		return {styles: st, classes: lineClasses.bgClass || lineClasses.textClass ? lineClasses : null};
	}

	function getLineStyles(cm, line) {
		if (!line.styles || line.styles[0] != cm.state.modeGen) {
			var result = highlightLine(cm, line, line.stateAfter = getStateBefore(cm, lineNo(line)));
			line.styles = result.styles;
			if (result.classes) line.styleClasses = result.classes;
			else if (line.styleClasses) line.styleClasses = null;
		}
		return line.styles;
	}

	// Lightweight form of highlight -- proceed over this line and
	// update state, but don't save a style array. Used for lines that
	// aren't currently visible.
	function processLine(cm, text, state, startAt) {
		var mode = cm.doc.mode;
		var stream = new StringStream(text, cm.options.tabSize);
		stream.start = stream.pos = startAt || 0;
		if (text == "") callBlankLine(mode, state);
		while (!stream.eol() && stream.pos <= cm.options.maxHighlightLength) {
			readToken(mode, stream, state);
			stream.start = stream.pos;
		}
	}

	// Convert a style as returned by a mode (either null, or a string
	// containing one or more styles) to a CSS style. This is cached,
	// and also looks for line-wide styles.
	var styleToClassCache = {}, styleToClassCacheWithMode = {};
	function interpretTokenStyle(style, options) {
		if (!style || /^\s*$/.test(style)) return null;
		var cache = options.addModeClass ? styleToClassCacheWithMode : styleToClassCache;
		return cache[style] ||
			(cache[style] = style.replace(/\S+/g, "cm-$&"));
	}

	// Render the DOM representation of the text of a line. Also builds
	// up a 'line map', which points at the DOM nodes that represent
	// specific stretches of text, and is used by the measuring code.
	// The returned object contains the DOM node, this map, and
	// information about line-wide styles that were set by the mode.
	function buildLineContent(cm, lineView) {
		// The padding-right forces the element to have a 'border', which
		// is needed on Webkit to be able to get line-level bounding
		// rectangles for it (in measureChar).
		var content = elt("span", null, null, webkit ? "padding-right: .1px" : null);
		var builder = {pre: elt("pre", [content]), content: content, col: 0, pos: 0, cm: cm};
		lineView.measure = {};

		// Iterate over the logical lines that make up this visual line.
		for (var i = 0; i <= (lineView.rest ? lineView.rest.length : 0); i++) {
			var line = i ? lineView.rest[i - 1] : lineView.line, order;
			builder.pos = 0;
			builder.addToken = buildToken;
			// Optionally wire in some hacks into the token-rendering
			// algorithm, to deal with browser quirks.
			if ((ie || webkit) && cm.getOption("lineWrapping"))
				builder.addToken = buildTokenSplitSpaces(builder.addToken);
			if (hasBadBidiRects(cm.display.measure) && (order = getOrder(line)))
				builder.addToken = buildTokenBadBidi(builder.addToken, order);
			builder.map = [];
			insertLineContent(line, builder, getLineStyles(cm, line));
			if (line.styleClasses) {
				if (line.styleClasses.bgClass)
					builder.bgClass = joinClasses(line.styleClasses.bgClass, builder.bgClass || "");
				if (line.styleClasses.textClass)
					builder.textClass = joinClasses(line.styleClasses.textClass, builder.textClass || "");
			}

			// Ensure at least a single node is present, for measuring.
			if (builder.map.length == 0)
				builder.map.push(0, 0, builder.content.appendChild(zeroWidthElement(cm.display.measure)));

			// Store the map and a cache object for the current logical line
			if (i == 0) {
				lineView.measure.map = builder.map;
				lineView.measure.cache = {};
			} else {
				(lineView.measure.maps || (lineView.measure.maps = [])).push(builder.map);
				(lineView.measure.caches || (lineView.measure.caches = [])).push({});
			}
		}

		signal(cm, "renderLine", cm, lineView.line, builder.pre);
		if (builder.pre.className)
			builder.textClass = joinClasses(builder.pre.className, builder.textClass || "");
		return builder;
	}

	function defaultSpecialCharPlaceholder(ch) {
		var token = elt("span", "\u2022", "cm-invalidchar");
		token.title = "\\u" + ch.charCodeAt(0).toString(16);
		return token;
	}

	// Build up the DOM representation for a single token, and add it to
	// the line map. Takes care to render special characters separately.
	function buildToken(builder, text, style, startStyle, endStyle, title) {
		if (!text) return;
		var special = builder.cm.options.specialChars, mustWrap = false;
		if (!special.test(text)) {
			builder.col += text.length;
			var content = document.createTextNode(text);
			builder.map.push(builder.pos, builder.pos + text.length, content);
			if (ie && ie_version < 9) mustWrap = true;
			builder.pos += text.length;
		} else {
			var content = document.createDocumentFragment(), pos = 0;
			while (true) {
				special.lastIndex = pos;
				var m = special.exec(text);
				var skipped = m ? m.index - pos : text.length - pos;
				if (skipped) {
					var txt = document.createTextNode(text.slice(pos, pos + skipped));
					if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
					else content.appendChild(txt);
					builder.map.push(builder.pos, builder.pos + skipped, txt);
					builder.col += skipped;
					builder.pos += skipped;
				}
				if (!m) break;
				pos += skipped + 1;
				if (m[0] == "\t") {
					var tabSize = builder.cm.options.tabSize, tabWidth = tabSize - builder.col % tabSize;
					var txt = content.appendChild(elt("span", spaceStr(tabWidth), "cm-tab"));
					builder.col += tabWidth;
				} else {
					var txt = builder.cm.options.specialCharPlaceholder(m[0]);
					if (ie && ie_version < 9) content.appendChild(elt("span", [txt]));
					else content.appendChild(txt);
					builder.col += 1;
				}
				builder.map.push(builder.pos, builder.pos + 1, txt);
				builder.pos++;
			}
		}
		if (style || startStyle || endStyle || mustWrap) {
			var fullStyle = style || "";
			if (startStyle) fullStyle += startStyle;
			if (endStyle) fullStyle += endStyle;
			var token = elt("span", [content], fullStyle);
			if (title) token.title = title;
			return builder.content.appendChild(token);
		}
		builder.content.appendChild(content);
	}

	function buildTokenSplitSpaces(inner) {
		function split(old) {
			var out = " ";
			for (var i = 0; i < old.length - 2; ++i) out += i % 2 ? " " : "\u00a0";
			out += " ";
			return out;
		}
		return function(builder, text, style, startStyle, endStyle, title) {
			inner(builder, text.replace(/ {3,}/g, split), style, startStyle, endStyle, title);
		};
	}

	// Work around nonsense dimensions being reported for stretches of
	// right-to-left text.
	function buildTokenBadBidi(inner, order) {
		return function(builder, text, style, startStyle, endStyle, title) {
			style = style ? style + " cm-force-border" : "cm-force-border";
			var start = builder.pos, end = start + text.length;
			for (;;) {
				// Find the part that overlaps with the start of this text
				for (var i = 0; i < order.length; i++) {
					var part = order[i];
					if (part.to > start && part.from <= start) break;
				}
				if (part.to >= end) return inner(builder, text, style, startStyle, endStyle, title);
				inner(builder, text.slice(0, part.to - start), style, startStyle, null, title);
				startStyle = null;
				text = text.slice(part.to - start);
				start = part.to;
			}
		};
	}

	function buildCollapsedSpan(builder, size, marker, ignoreWidget) {
		var widget = !ignoreWidget && marker.widgetNode;
		if (widget) {
			builder.map.push(builder.pos, builder.pos + size, widget);
			builder.content.appendChild(widget);
		}
		builder.pos += size;
	}

	// Outputs a number of spans to make up a line, taking highlighting
	// and marked text into account.
	function insertLineContent(line, builder, styles) {
		var spans = line.markedSpans, allText = line.text, at = 0;
		if (!spans) {
			for (var i = 1; i < styles.length; i+=2)
				builder.addToken(builder, allText.slice(at, at = styles[i]), interpretTokenStyle(styles[i+1], builder.cm.options));
			return;
		}

		var len = allText.length, pos = 0, i = 1, text = "", style;
		var nextChange = 0, spanStyle, spanEndStyle, spanStartStyle, title, collapsed;
		for (;;) {
			if (nextChange == pos) { // Update current marker set
				spanStyle = spanEndStyle = spanStartStyle = title = "";
				collapsed = null; nextChange = Infinity;
				var foundBookmarks = [];
				for (var j = 0; j < spans.length; ++j) {
					var sp = spans[j], m = sp.marker;
					if (sp.from <= pos && (sp.to == null || sp.to > pos)) {
						if (sp.to != null && nextChange > sp.to) { nextChange = sp.to; spanEndStyle = ""; }
						if (m.className) spanStyle += " " + m.className;
						if (m.startStyle && sp.from == pos) spanStartStyle += " " + m.startStyle;
						if (m.endStyle && sp.to == nextChange) spanEndStyle += " " + m.endStyle;
						if (m.title && !title) title = m.title;
						if (m.collapsed && (!collapsed || compareCollapsedMarkers(collapsed.marker, m) < 0))
							collapsed = sp;
					} else if (sp.from > pos && nextChange > sp.from) {
						nextChange = sp.from;
					}
					if (m.type == "bookmark" && sp.from == pos && m.widgetNode) foundBookmarks.push(m);
				}
				if (collapsed && (collapsed.from || 0) == pos) {
					buildCollapsedSpan(builder, (collapsed.to == null ? len + 1 : collapsed.to) - pos,
						collapsed.marker, collapsed.from == null);
					if (collapsed.to == null) return;
				}
				if (!collapsed && foundBookmarks.length) for (var j = 0; j < foundBookmarks.length; ++j)
					buildCollapsedSpan(builder, 0, foundBookmarks[j]);
			}
			if (pos >= len) break;

			var upto = Math.min(len, nextChange);
			while (true) {
				if (text) {
					var end = pos + text.length;
					if (!collapsed) {
						var tokenText = end > upto ? text.slice(0, upto - pos) : text;
						builder.addToken(builder, tokenText, style ? style + spanStyle : spanStyle,
							spanStartStyle, pos + tokenText.length == nextChange ? spanEndStyle : "", title);
					}
					if (end >= upto) {text = text.slice(upto - pos); pos = upto; break;}
					pos = end;
					spanStartStyle = "";
				}
				text = allText.slice(at, at = styles[i++]);
				style = interpretTokenStyle(styles[i++], builder.cm.options);
			}
		}
	}

	// DOCUMENT DATA STRUCTURE

	// By default, updates that start and end at the beginning of a line
	// are treated specially, in order to make the association of line
	// widgets and marker elements with the text behave more intuitive.
	function isWholeLineUpdate(doc, change) {
		return change.from.ch == 0 && change.to.ch == 0 && lst(change.text) == "" &&
			(!doc.cm || doc.cm.options.wholeLineUpdateBefore);
	}

	// Perform a change on the document data structure.
	function updateDoc(doc, change, markedSpans, estimateHeight) {
		function spansFor(n) {return markedSpans ? markedSpans[n] : null;}
		function update(line, text, spans) {
			updateLine(line, text, spans, estimateHeight);
			signalLater(line, "change", line, change);
		}

		var from = change.from, to = change.to, text = change.text;
		var firstLine = getLine(doc, from.line), lastLine = getLine(doc, to.line);
		var lastText = lst(text), lastSpans = spansFor(text.length - 1), nlines = to.line - from.line;

		// Adjust the line structure
		if (isWholeLineUpdate(doc, change)) {
			// This is a whole-line replace. Treated specially to make
			// sure line objects move the way they are supposed to.
			for (var i = 0, added = []; i < text.length - 1; ++i)
				added.push(new Line(text[i], spansFor(i), estimateHeight));
			update(lastLine, lastLine.text, lastSpans);
			if (nlines) doc.remove(from.line, nlines);
			if (added.length) doc.insert(from.line, added);
		} else if (firstLine == lastLine) {
			if (text.length == 1) {
				update(firstLine, firstLine.text.slice(0, from.ch) + lastText + firstLine.text.slice(to.ch), lastSpans);
			} else {
				for (var added = [], i = 1; i < text.length - 1; ++i)
					added.push(new Line(text[i], spansFor(i), estimateHeight));
				added.push(new Line(lastText + firstLine.text.slice(to.ch), lastSpans, estimateHeight));
				update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
				doc.insert(from.line + 1, added);
			}
		} else if (text.length == 1) {
			update(firstLine, firstLine.text.slice(0, from.ch) + text[0] + lastLine.text.slice(to.ch), spansFor(0));
			doc.remove(from.line + 1, nlines);
		} else {
			update(firstLine, firstLine.text.slice(0, from.ch) + text[0], spansFor(0));
			update(lastLine, lastText + lastLine.text.slice(to.ch), lastSpans);
			for (var i = 1, added = []; i < text.length - 1; ++i)
				added.push(new Line(text[i], spansFor(i), estimateHeight));
			if (nlines > 1) doc.remove(from.line + 1, nlines - 1);
			doc.insert(from.line + 1, added);
		}

		signalLater(doc, "change", doc, change);
	}

	// The document is represented as a BTree consisting of leaves, with
	// chunk of lines in them, and branches, with up to ten leaves or
	// other branch nodes below them. The top node is always a branch
	// node, and is the document object itself (meaning it has
	// additional methods and properties).
	//
	// All nodes have parent links. The tree is used both to go from
	// line numbers to line objects, and to go from objects to numbers.
	// It also indexes by height, and is used to convert between height
	// and line object, and to find the total height of the document.
	//
	// See also http://marijnhaverbeke.nl/blog/codemirror-line-tree.html

	function LeafChunk(lines) {
		this.lines = lines;
		this.parent = null;
		for (var i = 0, height = 0; i < lines.length; ++i) {
			lines[i].parent = this;
			height += lines[i].height;
		}
		this.height = height;
	}

	LeafChunk.prototype = {
		chunkSize: function() { return this.lines.length; },
		// Remove the n lines at offset 'at'.
		removeInner: function(at, n) {
			for (var i = at, e = at + n; i < e; ++i) {
				var line = this.lines[i];
				this.height -= line.height;
				cleanUpLine(line);
				signalLater(line, "delete");
			}
			this.lines.splice(at, n);
		},
		// Helper used to collapse a small branch into a single leaf.
		collapse: function(lines) {
			lines.push.apply(lines, this.lines);
		},
		// Insert the given array of lines at offset 'at', count them as
		// having the given height.
		insertInner: function(at, lines, height) {
			this.height += height;
			this.lines = this.lines.slice(0, at).concat(lines).concat(this.lines.slice(at));
			for (var i = 0; i < lines.length; ++i) lines[i].parent = this;
		},
		// Used to iterate over a part of the tree.
		iterN: function(at, n, op) {
			for (var e = at + n; at < e; ++at)
				if (op(this.lines[at])) return true;
		}
	};

	function BranchChunk(children) {
		this.children = children;
		var size = 0, height = 0;
		for (var i = 0; i < children.length; ++i) {
			var ch = children[i];
			size += ch.chunkSize(); height += ch.height;
			ch.parent = this;
		}
		this.size = size;
		this.height = height;
		this.parent = null;
	}

	BranchChunk.prototype = {
		chunkSize: function() { return this.size; },
		removeInner: function(at, n) {
			this.size -= n;
			for (var i = 0; i < this.children.length; ++i) {
				var child = this.children[i], sz = child.chunkSize();
				if (at < sz) {
					var rm = Math.min(n, sz - at), oldHeight = child.height;
					child.removeInner(at, rm);
					this.height -= oldHeight - child.height;
					if (sz == rm) { this.children.splice(i--, 1); child.parent = null; }
					if ((n -= rm) == 0) break;
					at = 0;
				} else at -= sz;
			}
			// If the result is smaller than 25 lines, ensure that it is a
			// single leaf node.
			if (this.size - n < 25 &&
				(this.children.length > 1 || !(this.children[0] instanceof LeafChunk))) {
				var lines = [];
				this.collapse(lines);
				this.children = [new LeafChunk(lines)];
				this.children[0].parent = this;
			}
		},
		collapse: function(lines) {
			for (var i = 0; i < this.children.length; ++i) this.children[i].collapse(lines);
		},
		insertInner: function(at, lines, height) {
			this.size += lines.length;
			this.height += height;
			for (var i = 0; i < this.children.length; ++i) {
				var child = this.children[i], sz = child.chunkSize();
				if (at <= sz) {
					child.insertInner(at, lines, height);
					if (child.lines && child.lines.length > 50) {
						while (child.lines.length > 50) {
							var spilled = child.lines.splice(child.lines.length - 25, 25);
							var newleaf = new LeafChunk(spilled);
							child.height -= newleaf.height;
							this.children.splice(i + 1, 0, newleaf);
							newleaf.parent = this;
						}
						this.maybeSpill();
					}
					break;
				}
				at -= sz;
			}
		},
		// When a node has grown, check whether it should be split.
		maybeSpill: function() {
			if (this.children.length <= 10) return;
			var me = this;
			do {
				var spilled = me.children.splice(me.children.length - 5, 5);
				var sibling = new BranchChunk(spilled);
				if (!me.parent) { // Become the parent node
					var copy = new BranchChunk(me.children);
					copy.parent = me;
					me.children = [copy, sibling];
					me = copy;
				} else {
					me.size -= sibling.size;
					me.height -= sibling.height;
					var myIndex = indexOf(me.parent.children, me);
					me.parent.children.splice(myIndex + 1, 0, sibling);
				}
				sibling.parent = me.parent;
			} while (me.children.length > 10);
			me.parent.maybeSpill();
		},
		iterN: function(at, n, op) {
			for (var i = 0; i < this.children.length; ++i) {
				var child = this.children[i], sz = child.chunkSize();
				if (at < sz) {
					var used = Math.min(n, sz - at);
					if (child.iterN(at, used, op)) return true;
					if ((n -= used) == 0) break;
					at = 0;
				} else at -= sz;
			}
		}
	};

	var nextDocId = 0;
	var Doc = CodeMirror.Doc = function(text, mode, firstLine) {
		if (!(this instanceof Doc)) return new Doc(text, mode, firstLine);
		if (firstLine == null) firstLine = 0;

		BranchChunk.call(this, [new LeafChunk([new Line("", null)])]);
		this.first = firstLine;
		this.scrollTop = this.scrollLeft = 0;
		this.cantEdit = false;
		this.cleanGeneration = 1;
		this.frontier = firstLine;
		var start = Pos(firstLine, 0);
		this.sel = simpleSelection(start);
		this.history = new History(null);
		this.id = ++nextDocId;
		this.modeOption = mode;

		if (typeof text == "string") text = splitLines(text);
		updateDoc(this, {from: start, to: start, text: text});
		setSelection(this, simpleSelection(start), sel_dontScroll);
	};

	Doc.prototype = createObj(BranchChunk.prototype, {
		constructor: Doc,
		// Iterate over the document. Supports two forms -- with only one
		// argument, it calls that for each line in the document. With
		// three, it iterates over the range given by the first two (with
		// the second being non-inclusive).
		iter: function(from, to, op) {
			if (op) this.iterN(from - this.first, to - from, op);
			else this.iterN(this.first, this.first + this.size, from);
		},

		// Non-public interface for adding and removing lines.
		insert: function(at, lines) {
			var height = 0;
			for (var i = 0; i < lines.length; ++i) height += lines[i].height;
			this.insertInner(at - this.first, lines, height);
		},
		remove: function(at, n) { this.removeInner(at - this.first, n); },

		// From here, the methods are part of the public interface. Most
		// are also available from CodeMirror (editor) instances.

		getValue: function(lineSep) {
			var lines = getLines(this, this.first, this.first + this.size);
			if (lineSep === false) return lines;
			return lines.join(lineSep || "\n");
		},
		setValue: docMethodOp(function(code) {
			var top = Pos(this.first, 0), last = this.first + this.size - 1;
			makeChange(this, {from: top, to: Pos(last, getLine(this, last).text.length),
				text: splitLines(code), origin: "setValue"}, true);
			setSelection(this, simpleSelection(top));
		}),
		replaceRange: function(code, from, to, origin) {
			from = clipPos(this, from);
			to = to ? clipPos(this, to) : from;
			replaceRange(this, code, from, to, origin);
		},
		getRange: function(from, to, lineSep) {
			var lines = getBetween(this, clipPos(this, from), clipPos(this, to));
			if (lineSep === false) return lines;
			return lines.join(lineSep || "\n");
		},

		getLine: function(line) {var l = this.getLineHandle(line); return l && l.text;},

		getLineHandle: function(line) {if (isLine(this, line)) return getLine(this, line);},
		getLineNumber: function(line) {return lineNo(line);},

		getLineHandleVisualStart: function(line) {
			if (typeof line == "number") line = getLine(this, line);
			return visualLine(line);
		},

		lineCount: function() {return this.size;},
		firstLine: function() {return this.first;},
		lastLine: function() {return this.first + this.size - 1;},

		clipPos: function(pos) {return clipPos(this, pos);},

		getCursor: function(start) {
			var range = this.sel.primary(), pos;
			if (start == null || start == "head") pos = range.head;
			else if (start == "anchor") pos = range.anchor;
			else if (start == "end" || start == "to" || start === false) pos = range.to();
			else pos = range.from();
			return pos;
		},
		listSelections: function() { return this.sel.ranges; },
		somethingSelected: function() {return this.sel.somethingSelected();},

		setCursor: docMethodOp(function(line, ch, options) {
			setSimpleSelection(this, clipPos(this, typeof line == "number" ? Pos(line, ch || 0) : line), null, options);
		}),
		setSelection: docMethodOp(function(anchor, head, options) {
			setSimpleSelection(this, clipPos(this, anchor), clipPos(this, head || anchor), options);
		}),
		extendSelection: docMethodOp(function(head, other, options) {
			extendSelection(this, clipPos(this, head), other && clipPos(this, other), options);
		}),
		extendSelections: docMethodOp(function(heads, options) {
			extendSelections(this, clipPosArray(this, heads, options));
		}),
		extendSelectionsBy: docMethodOp(function(f, options) {
			extendSelections(this, map(this.sel.ranges, f), options);
		}),
		setSelections: docMethodOp(function(ranges, primary, options) {
			if (!ranges.length) return;
			for (var i = 0, out = []; i < ranges.length; i++)
				out[i] = new Range(clipPos(this, ranges[i].anchor),
					clipPos(this, ranges[i].head));
			if (primary == null) primary = Math.min(ranges.length - 1, this.sel.primIndex);
			setSelection(this, normalizeSelection(out, primary), options);
		}),
		addSelection: docMethodOp(function(anchor, head, options) {
			var ranges = this.sel.ranges.slice(0);
			ranges.push(new Range(clipPos(this, anchor), clipPos(this, head || anchor)));
			setSelection(this, normalizeSelection(ranges, ranges.length - 1), options);
		}),

		getSelection: function(lineSep) {
			var ranges = this.sel.ranges, lines;
			for (var i = 0; i < ranges.length; i++) {
				var sel = getBetween(this, ranges[i].from(), ranges[i].to());
				lines = lines ? lines.concat(sel) : sel;
			}
			if (lineSep === false) return lines;
			else return lines.join(lineSep || "\n");
		},
		getSelections: function(lineSep) {
			var parts = [], ranges = this.sel.ranges;
			for (var i = 0; i < ranges.length; i++) {
				var sel = getBetween(this, ranges[i].from(), ranges[i].to());
				if (lineSep !== false) sel = sel.join(lineSep || "\n");
				parts[i] = sel;
			}
			return parts;
		},
		replaceSelection: function(code, collapse, origin) {
			var dup = [];
			for (var i = 0; i < this.sel.ranges.length; i++)
				dup[i] = code;
			this.replaceSelections(dup, collapse, origin || "+input");
		},
		replaceSelections: docMethodOp(function(code, collapse, origin) {
			var changes = [], sel = this.sel;
			for (var i = 0; i < sel.ranges.length; i++) {
				var range = sel.ranges[i];
				changes[i] = {from: range.from(), to: range.to(), text: splitLines(code[i]), origin: origin};
			}
			var newSel = collapse && collapse != "end" && computeReplacedSel(this, changes, collapse);
			for (var i = changes.length - 1; i >= 0; i--)
				makeChange(this, changes[i]);
			if (newSel) setSelectionReplaceHistory(this, newSel);
			else if (this.cm) ensureCursorVisible(this.cm);
		}),
		undo: docMethodOp(function() {makeChangeFromHistory(this, "undo");}),
		redo: docMethodOp(function() {makeChangeFromHistory(this, "redo");}),
		undoSelection: docMethodOp(function() {makeChangeFromHistory(this, "undo", true);}),
		redoSelection: docMethodOp(function() {makeChangeFromHistory(this, "redo", true);}),

		setExtending: function(val) {this.extend = val;},
		getExtending: function() {return this.extend;},

		historySize: function() {
			var hist = this.history, done = 0, undone = 0;
			for (var i = 0; i < hist.done.length; i++) if (!hist.done[i].ranges) ++done;
			for (var i = 0; i < hist.undone.length; i++) if (!hist.undone[i].ranges) ++undone;
			return {undo: done, redo: undone};
		},
		clearHistory: function() {this.history = new History(this.history.maxGeneration);},

		markClean: function() {
			this.cleanGeneration = this.changeGeneration(true);
		},
		changeGeneration: function(forceSplit) {
			if (forceSplit)
				this.history.lastOp = this.history.lastOrigin = null;
			return this.history.generation;
		},
		isClean: function (gen) {
			return this.history.generation == (gen || this.cleanGeneration);
		},

		getHistory: function() {
			return {done: copyHistoryArray(this.history.done),
				undone: copyHistoryArray(this.history.undone)};
		},
		setHistory: function(histData) {
			var hist = this.history = new History(this.history.maxGeneration);
			hist.done = copyHistoryArray(histData.done.slice(0), null, true);
			hist.undone = copyHistoryArray(histData.undone.slice(0), null, true);
		},

		addLineClass: docMethodOp(function(handle, where, cls) {
			return changeLine(this, handle, "class", function(line) {
				var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
				if (!line[prop]) line[prop] = cls;
				else if (new RegExp("(?:^|\\s)" + cls + "(?:$|\\s)").test(line[prop])) return false;
				else line[prop] += " " + cls;
				return true;
			});
		}),
		removeLineClass: docMethodOp(function(handle, where, cls) {
			return changeLine(this, handle, "class", function(line) {
				var prop = where == "text" ? "textClass" : where == "background" ? "bgClass" : "wrapClass";
				var cur = line[prop];
				if (!cur) return false;
				else if (cls == null) line[prop] = null;
				else {
					var found = cur.match(new RegExp("(?:^|\\s+)" + cls + "(?:$|\\s+)"));
					if (!found) return false;
					var end = found.index + found[0].length;
					line[prop] = cur.slice(0, found.index) + (!found.index || end == cur.length ? "" : " ") + cur.slice(end) || null;
				}
				return true;
			});
		}),

		markText: function(from, to, options) {
			return markText(this, clipPos(this, from), clipPos(this, to), options, "range");
		},
		setBookmark: function(pos, options) {
			var realOpts = {replacedWith: options && (options.nodeType == null ? options.widget : options),
				insertLeft: options && options.insertLeft,
				clearWhenEmpty: false, shared: options && options.shared};
			pos = clipPos(this, pos);
			return markText(this, pos, pos, realOpts, "bookmark");
		},
		findMarksAt: function(pos) {
			pos = clipPos(this, pos);
			var markers = [], spans = getLine(this, pos.line).markedSpans;
			if (spans) for (var i = 0; i < spans.length; ++i) {
				var span = spans[i];
				if ((span.from == null || span.from <= pos.ch) &&
					(span.to == null || span.to >= pos.ch))
					markers.push(span.marker.parent || span.marker);
			}
			return markers;
		},
		findMarks: function(from, to, filter) {
			from = clipPos(this, from); to = clipPos(this, to);
			var found = [], lineNo = from.line;
			this.iter(from.line, to.line + 1, function(line) {
				var spans = line.markedSpans;
				if (spans) for (var i = 0; i < spans.length; i++) {
					var span = spans[i];
					if (!(lineNo == from.line && from.ch > span.to ||
						span.from == null && lineNo != from.line||
						lineNo == to.line && span.from > to.ch) &&
						(!filter || filter(span.marker)))
						found.push(span.marker.parent || span.marker);
				}
				++lineNo;
			});
			return found;
		},
		getAllMarks: function() {
			var markers = [];
			this.iter(function(line) {
				var sps = line.markedSpans;
				if (sps) for (var i = 0; i < sps.length; ++i)
					if (sps[i].from != null) markers.push(sps[i].marker);
			});
			return markers;
		},

		posFromIndex: function(off) {
			var ch, lineNo = this.first;
			this.iter(function(line) {
				var sz = line.text.length + 1;
				if (sz > off) { ch = off; return true; }
				off -= sz;
				++lineNo;
			});
			return clipPos(this, Pos(lineNo, ch));
		},
		indexFromPos: function (coords) {
			coords = clipPos(this, coords);
			var index = coords.ch;
			if (coords.line < this.first || coords.ch < 0) return 0;
			this.iter(this.first, coords.line, function (line) {
				index += line.text.length + 1;
			});
			return index;
		},

		copy: function(copyHistory) {
			var doc = new Doc(getLines(this, this.first, this.first + this.size), this.modeOption, this.first);
			doc.scrollTop = this.scrollTop; doc.scrollLeft = this.scrollLeft;
			doc.sel = this.sel;
			doc.extend = false;
			if (copyHistory) {
				doc.history.undoDepth = this.history.undoDepth;
				doc.setHistory(this.getHistory());
			}
			return doc;
		},

		linkedDoc: function(options) {
			if (!options) options = {};
			var from = this.first, to = this.first + this.size;
			if (options.from != null && options.from > from) from = options.from;
			if (options.to != null && options.to < to) to = options.to;
			var copy = new Doc(getLines(this, from, to), options.mode || this.modeOption, from);
			if (options.sharedHist) copy.history = this.history;
			(this.linked || (this.linked = [])).push({doc: copy, sharedHist: options.sharedHist});
			copy.linked = [{doc: this, isParent: true, sharedHist: options.sharedHist}];
			copySharedMarkers(copy, findSharedMarkers(this));
			return copy;
		},
		unlinkDoc: function(other) {
			if (other instanceof CodeMirror) other = other.doc;
			if (this.linked) for (var i = 0; i < this.linked.length; ++i) {
				var link = this.linked[i];
				if (link.doc != other) continue;
				this.linked.splice(i, 1);
				other.unlinkDoc(this);
				detachSharedMarkers(findSharedMarkers(this));
				break;
			}
			// If the histories were shared, split them again
			if (other.history == this.history) {
				var splitIds = [other.id];
				linkedDocs(other, function(doc) {splitIds.push(doc.id);}, true);
				other.history = new History(null);
				other.history.done = copyHistoryArray(this.history.done, splitIds);
				other.history.undone = copyHistoryArray(this.history.undone, splitIds);
			}
		},
		iterLinkedDocs: function(f) {linkedDocs(this, f);},

		getMode: function() {return this.mode;},
		getEditor: function() {return this.cm;}
	});

	// Public alias.
	Doc.prototype.eachLine = Doc.prototype.iter;

	// Set up methods on CodeMirror's prototype to redirect to the editor's document.
	var dontDelegate = "iter insert remove copy getEditor".split(" ");
	for (var prop in Doc.prototype) if (Doc.prototype.hasOwnProperty(prop) && indexOf(dontDelegate, prop) < 0)
		CodeMirror.prototype[prop] = (function(method) {
			return function() {return method.apply(this.doc, arguments);};
		})(Doc.prototype[prop]);

	eventMixin(Doc);

	// Call f for all linked documents.
	function linkedDocs(doc, f, sharedHistOnly) {
		function propagate(doc, skip, sharedHist) {
			if (doc.linked) for (var i = 0; i < doc.linked.length; ++i) {
				var rel = doc.linked[i];
				if (rel.doc == skip) continue;
				var shared = sharedHist && rel.sharedHist;
				if (sharedHistOnly && !shared) continue;
				f(rel.doc, shared);
				propagate(rel.doc, doc, shared);
			}
		}
		propagate(doc, null, true);
	}

	// Attach a document to an editor.
	function attachDoc(cm, doc) {
		if (doc.cm) throw new Error("This document is already in use.");
		cm.doc = doc;
		doc.cm = cm;
		estimateLineHeights(cm);
		loadMode(cm);
		if (!cm.options.lineWrapping) findMaxLine(cm);
		cm.options.mode = doc.modeOption;
		regChange(cm);
	}

	// LINE UTILITIES

	// Find the line object corresponding to the given line number.
	function getLine(doc, n) {
		n -= doc.first;
		if (n < 0 || n >= doc.size) throw new Error("There is no line " + (n + doc.first) + " in the document.");
		for (var chunk = doc; !chunk.lines;) {
			for (var i = 0;; ++i) {
				var child = chunk.children[i], sz = child.chunkSize();
				if (n < sz) { chunk = child; break; }
				n -= sz;
			}
		}
		return chunk.lines[n];
	}

	// Get the part of a document between two positions, as an array of
	// strings.
	function getBetween(doc, start, end) {
		var out = [], n = start.line;
		doc.iter(start.line, end.line + 1, function(line) {
			var text = line.text;
			if (n == end.line) text = text.slice(0, end.ch);
			if (n == start.line) text = text.slice(start.ch);
			out.push(text);
			++n;
		});
		return out;
	}
	// Get the lines between from and to, as array of strings.
	function getLines(doc, from, to) {
		var out = [];
		doc.iter(from, to, function(line) { out.push(line.text); });
		return out;
	}

	// Update the height of a line, propagating the height change
	// upwards to parent nodes.
	function updateLineHeight(line, height) {
		var diff = height - line.height;
		if (diff) for (var n = line; n; n = n.parent) n.height += diff;
	}

	// Given a line object, find its line number by walking up through
	// its parent links.
	function lineNo(line) {
		if (line.parent == null) return null;
		var cur = line.parent, no = indexOf(cur.lines, line);
		for (var chunk = cur.parent; chunk; cur = chunk, chunk = chunk.parent) {
			for (var i = 0;; ++i) {
				if (chunk.children[i] == cur) break;
				no += chunk.children[i].chunkSize();
			}
		}
		return no + cur.first;
	}

	// Find the line at the given vertical position, using the height
	// information in the document tree.
	function lineAtHeight(chunk, h) {
		var n = chunk.first;
		outer: do {
			for (var i = 0; i < chunk.children.length; ++i) {
				var child = chunk.children[i], ch = child.height;
				if (h < ch) { chunk = child; continue outer; }
				h -= ch;
				n += child.chunkSize();
			}
			return n;
		} while (!chunk.lines);
		for (var i = 0; i < chunk.lines.length; ++i) {
			var line = chunk.lines[i], lh = line.height;
			if (h < lh) break;
			h -= lh;
		}
		return n + i;
	}


	// Find the height above the given line.
	function heightAtLine(lineObj) {
		lineObj = visualLine(lineObj);

		var h = 0, chunk = lineObj.parent;
		for (var i = 0; i < chunk.lines.length; ++i) {
			var line = chunk.lines[i];
			if (line == lineObj) break;
			else h += line.height;
		}
		for (var p = chunk.parent; p; chunk = p, p = chunk.parent) {
			for (var i = 0; i < p.children.length; ++i) {
				var cur = p.children[i];
				if (cur == chunk) break;
				else h += cur.height;
			}
		}
		return h;
	}

	// Get the bidi ordering for the given line (and cache it). Returns
	// false for lines that are fully left-to-right, and an array of
	// BidiSpan objects otherwise.
	function getOrder(line) {
		var order = line.order;
		if (order == null) order = line.order = bidiOrdering(line.text);
		return order;
	}

	// HISTORY

	function History(startGen) {
		// Arrays of change events and selections. Doing something adds an
		// event to done and clears undo. Undoing moves events from done
		// to undone, redoing moves them in the other direction.
		this.done = []; this.undone = [];
		this.undoDepth = Infinity;
		// Used to track when changes can be merged into a single undo
		// event
		this.lastModTime = this.lastSelTime = 0;
		this.lastOp = null;
		this.lastOrigin = this.lastSelOrigin = null;
		// Used by the isClean() method
		this.generation = this.maxGeneration = startGen || 1;
	}

	// Create a history change event from an updateDoc-style change
	// object.
	function historyChangeFromChange(doc, change) {
		var histChange = {from: copyPos(change.from), to: changeEnd(change), text: getBetween(doc, change.from, change.to)};
		attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);
		linkedDocs(doc, function(doc) {attachLocalSpans(doc, histChange, change.from.line, change.to.line + 1);}, true);
		return histChange;
	}

	// Pop all selection events off the end of a history array. Stop at
	// a change event.
	function clearSelectionEvents(array) {
		while (array.length) {
			var last = lst(array);
			if (last.ranges) array.pop();
			else break;
		}
	}

	// Find the top change event in the history. Pop off selection
	// events that are in the way.
	function lastChangeEvent(hist, force) {
		if (force) {
			clearSelectionEvents(hist.done);
			return lst(hist.done);
		} else if (hist.done.length && !lst(hist.done).ranges) {
			return lst(hist.done);
		} else if (hist.done.length > 1 && !hist.done[hist.done.length - 2].ranges) {
			hist.done.pop();
			return lst(hist.done);
		}
	}

	// Register a change in the history. Merges changes that are within
	// a single operation, ore are close together with an origin that
	// allows merging (starting with "+") into a single event.
	function addChangeToHistory(doc, change, selAfter, opId) {
		var hist = doc.history;
		hist.undone.length = 0;
		var time = +new Date, cur;

		if ((hist.lastOp == opId ||
			hist.lastOrigin == change.origin && change.origin &&
			((change.origin.charAt(0) == "+" && doc.cm && hist.lastModTime > time - doc.cm.options.historyEventDelay) ||
			change.origin.charAt(0) == "*")) &&
			(cur = lastChangeEvent(hist, hist.lastOp == opId))) {
			// Merge this change into the last event
			var last = lst(cur.changes);
			if (cmp(change.from, change.to) == 0 && cmp(change.from, last.to) == 0) {
				// Optimized case for simple insertion -- don't want to add
				// new changesets for every character typed
				last.to = changeEnd(change);
			} else {
				// Add new sub-event
				cur.changes.push(historyChangeFromChange(doc, change));
			}
		} else {
			// Can not be merged, start a new event.
			var before = lst(hist.done);
			if (!before || !before.ranges)
				pushSelectionToHistory(doc.sel, hist.done);
			cur = {changes: [historyChangeFromChange(doc, change)],
				generation: hist.generation};
			hist.done.push(cur);
			while (hist.done.length > hist.undoDepth) {
				hist.done.shift();
				if (!hist.done[0].ranges) hist.done.shift();
			}
		}
		hist.done.push(selAfter);
		hist.generation = ++hist.maxGeneration;
		hist.lastModTime = hist.lastSelTime = time;
		hist.lastOp = opId;
		hist.lastOrigin = hist.lastSelOrigin = change.origin;

		if (!last) signal(doc, "historyAdded");
	}

	function selectionEventCanBeMerged(doc, origin, prev, sel) {
		var ch = origin.charAt(0);
		return ch == "*" ||
			ch == "+" &&
			prev.ranges.length == sel.ranges.length &&
			prev.somethingSelected() == sel.somethingSelected() &&
			new Date - doc.history.lastSelTime <= (doc.cm ? doc.cm.options.historyEventDelay : 500);
	}

	// Called whenever the selection changes, sets the new selection as
	// the pending selection in the history, and pushes the old pending
	// selection into the 'done' array when it was significantly
	// different (in number of selected ranges, emptiness, or time).
	function addSelectionToHistory(doc, sel, opId, options) {
		var hist = doc.history, origin = options && options.origin;

		// A new event is started when the previous origin does not match
		// the current, or the origins don't allow matching. Origins
		// starting with * are always merged, those starting with + are
		// merged when similar and close together in time.
		if (opId == hist.lastOp ||
			(origin && hist.lastSelOrigin == origin &&
			(hist.lastModTime == hist.lastSelTime && hist.lastOrigin == origin ||
			selectionEventCanBeMerged(doc, origin, lst(hist.done), sel))))
			hist.done[hist.done.length - 1] = sel;
		else
			pushSelectionToHistory(sel, hist.done);

		hist.lastSelTime = +new Date;
		hist.lastSelOrigin = origin;
		hist.lastOp = opId;
		if (options && options.clearRedo !== false)
			clearSelectionEvents(hist.undone);
	}

	function pushSelectionToHistory(sel, dest) {
		var top = lst(dest);
		if (!(top && top.ranges && top.equals(sel)))
			dest.push(sel);
	}

	// Used to store marked span information in the history.
	function attachLocalSpans(doc, change, from, to) {
		var existing = change["spans_" + doc.id], n = 0;
		doc.iter(Math.max(doc.first, from), Math.min(doc.first + doc.size, to), function(line) {
			if (line.markedSpans)
				(existing || (existing = change["spans_" + doc.id] = {}))[n] = line.markedSpans;
			++n;
		});
	}

	// When un/re-doing restores text containing marked spans, those
	// that have been explicitly cleared should not be restored.
	function removeClearedSpans(spans) {
		if (!spans) return null;
		for (var i = 0, out; i < spans.length; ++i) {
			if (spans[i].marker.explicitlyCleared) { if (!out) out = spans.slice(0, i); }
			else if (out) out.push(spans[i]);
		}
		return !out ? spans : out.length ? out : null;
	}

	// Retrieve and filter the old marked spans stored in a change event.
	function getOldSpans(doc, change) {
		var found = change["spans_" + doc.id];
		if (!found) return null;
		for (var i = 0, nw = []; i < change.text.length; ++i)
			nw.push(removeClearedSpans(found[i]));
		return nw;
	}

	// Used both to provide a JSON-safe object in .getHistory, and, when
	// detaching a document, to split the history in two
	function copyHistoryArray(events, newGroup, instantiateSel) {
		for (var i = 0, copy = []; i < events.length; ++i) {
			var event = events[i];
			if (event.ranges) {
				copy.push(instantiateSel ? Selection.prototype.deepCopy.call(event) : event);
				continue;
			}
			var changes = event.changes, newChanges = [];
			copy.push({changes: newChanges});
			for (var j = 0; j < changes.length; ++j) {
				var change = changes[j], m;
				newChanges.push({from: change.from, to: change.to, text: change.text});
				if (newGroup) for (var prop in change) if (m = prop.match(/^spans_(\d+)$/)) {
					if (indexOf(newGroup, Number(m[1])) > -1) {
						lst(newChanges)[prop] = change[prop];
						delete change[prop];
					}
				}
			}
		}
		return copy;
	}

	// Rebasing/resetting history to deal with externally-sourced changes

	function rebaseHistSelSingle(pos, from, to, diff) {
		if (to < pos.line) {
			pos.line += diff;
		} else if (from < pos.line) {
			pos.line = from;
			pos.ch = 0;
		}
	}

	// Tries to rebase an array of history events given a change in the
	// document. If the change touches the same lines as the event, the
	// event, and everything 'behind' it, is discarded. If the change is
	// before the event, the event's positions are updated. Uses a
	// copy-on-write scheme for the positions, to avoid having to
	// reallocate them all on every rebase, but also avoid problems with
	// shared position objects being unsafely updated.
	function rebaseHistArray(array, from, to, diff) {
		for (var i = 0; i < array.length; ++i) {
			var sub = array[i], ok = true;
			if (sub.ranges) {
				if (!sub.copied) { sub = array[i] = sub.deepCopy(); sub.copied = true; }
				for (var j = 0; j < sub.ranges.length; j++) {
					rebaseHistSelSingle(sub.ranges[j].anchor, from, to, diff);
					rebaseHistSelSingle(sub.ranges[j].head, from, to, diff);
				}
				continue;
			}
			for (var j = 0; j < sub.changes.length; ++j) {
				var cur = sub.changes[j];
				if (to < cur.from.line) {
					cur.from = Pos(cur.from.line + diff, cur.from.ch);
					cur.to = Pos(cur.to.line + diff, cur.to.ch);
				} else if (from <= cur.to.line) {
					ok = false;
					break;
				}
			}
			if (!ok) {
				array.splice(0, i + 1);
				i = 0;
			}
		}
	}

	function rebaseHist(hist, change) {
		var from = change.from.line, to = change.to.line, diff = change.text.length - (to - from) - 1;
		rebaseHistArray(hist.done, from, to, diff);
		rebaseHistArray(hist.undone, from, to, diff);
	}

	// EVENT UTILITIES

	// Due to the fact that we still support jurassic IE versions, some
	// compatibility wrappers are needed.

	var e_preventDefault = CodeMirror.e_preventDefault = function(e) {
		if (e.preventDefault) e.preventDefault();
		else e.returnValue = false;
	};
	var e_stopPropagation = CodeMirror.e_stopPropagation = function(e) {
		if (e.stopPropagation) e.stopPropagation();
		else e.cancelBubble = true;
	};
	function e_defaultPrevented(e) {
		return e.defaultPrevented != null ? e.defaultPrevented : e.returnValue == false;
	}
	var e_stop = CodeMirror.e_stop = function(e) {e_preventDefault(e); e_stopPropagation(e);};

	function e_target(e) {return e.target || e.srcElement;}
	function e_button(e) {
		var b = e.which;
		if (b == null) {
			if (e.button & 1) b = 1;
			else if (e.button & 2) b = 3;
			else if (e.button & 4) b = 2;
		}
		if (mac && e.ctrlKey && b == 1) b = 3;
		return b;
	}

	// EVENT HANDLING

	// Lightweight event framework. on/off also work on DOM nodes,
	// registering native DOM handlers.

	var on = CodeMirror.on = function(emitter, type, f) {
		if (emitter.addEventListener)
			emitter.addEventListener(type, f, false);
		else if (emitter.attachEvent)
			emitter.attachEvent("on" + type, f);
		else {
			var map = emitter._handlers || (emitter._handlers = {});
			var arr = map[type] || (map[type] = []);
			arr.push(f);
		}
	};

	var off = CodeMirror.off = function(emitter, type, f) {
		if (emitter.removeEventListener)
			emitter.removeEventListener(type, f, false);
		else if (emitter.detachEvent)
			emitter.detachEvent("on" + type, f);
		else {
			var arr = emitter._handlers && emitter._handlers[type];
			if (!arr) return;
			for (var i = 0; i < arr.length; ++i)
				if (arr[i] == f) { arr.splice(i, 1); break; }
		}
	};

	var signal = CodeMirror.signal = function(emitter, type /*, values...*/) {
		var arr = emitter._handlers && emitter._handlers[type];
		if (!arr) return;
		var args = Array.prototype.slice.call(arguments, 2);
		for (var i = 0; i < arr.length; ++i) arr[i].apply(null, args);
	};

	// Often, we want to signal events at a point where we are in the
	// middle of some work, but don't want the handler to start calling
	// other methods on the editor, which might be in an inconsistent
	// state or simply not expect any other events to happen.
	// signalLater looks whether there are any handlers, and schedules
	// them to be executed when the last operation ends, or, if no
	// operation is active, when a timeout fires.
	var delayedCallbacks, delayedCallbackDepth = 0;
	function signalLater(emitter, type /*, values...*/) {
		var arr = emitter._handlers && emitter._handlers[type];
		if (!arr) return;
		var args = Array.prototype.slice.call(arguments, 2);
		if (!delayedCallbacks) {
			++delayedCallbackDepth;
			delayedCallbacks = [];
			setTimeout(fireDelayed, 0);
		}
		function bnd(f) {return function(){f.apply(null, args);};};
		for (var i = 0; i < arr.length; ++i)
			delayedCallbacks.push(bnd(arr[i]));
	}

	function fireDelayed() {
		--delayedCallbackDepth;
		var delayed = delayedCallbacks;
		delayedCallbacks = null;
		for (var i = 0; i < delayed.length; ++i) delayed[i]();
	}

	// The DOM events that CodeMirror handles can be overridden by
	// registering a (non-DOM) handler on the editor for the event name,
	// and preventDefault-ing the event in that handler.
	function signalDOMEvent(cm, e, override) {
		signal(cm, override || e.type, cm, e);
		return e_defaultPrevented(e) || e.codemirrorIgnore;
	}

	function signalCursorActivity(cm) {
		var arr = cm._handlers && cm._handlers.cursorActivity;
		if (!arr) return;
		var set = cm.curOp.cursorActivityHandlers || (cm.curOp.cursorActivityHandlers = []);
		for (var i = 0; i < arr.length; ++i) if (indexOf(set, arr[i]) == -1)
			set.push(arr[i]);
	}

	function hasHandler(emitter, type) {
		var arr = emitter._handlers && emitter._handlers[type];
		return arr && arr.length > 0;
	}

	// Add on and off methods to a constructor's prototype, to make
	// registering events on such objects more convenient.
	function eventMixin(ctor) {
		ctor.prototype.on = function(type, f) {on(this, type, f);};
		ctor.prototype.off = function(type, f) {off(this, type, f);};
	}

	// MISC UTILITIES

	// Number of pixels added to scroller and sizer to hide scrollbar
	var scrollerCutOff = 30;

	// Returned or thrown by various protocols to signal 'I'm not
	// handling this'.
	var Pass = CodeMirror.Pass = {toString: function(){return "CodeMirror.Pass";}};

	// Reused option objects for setSelection & friends
	var sel_dontScroll = {scroll: false}, sel_mouse = {origin: "*mouse"}, sel_move = {origin: "+move"};

	function Delayed() {this.id = null;}
	Delayed.prototype.set = function(ms, f) {
		clearTimeout(this.id);
		this.id = setTimeout(f, ms);
	};

	// Counts the column offset in a string, taking tabs into account.
	// Used mostly to find indentation.
	var countColumn = CodeMirror.countColumn = function(string, end, tabSize, startIndex, startValue) {
		if (end == null) {
			end = string.search(/[^\s\u00a0]/);
			if (end == -1) end = string.length;
		}
		for (var i = startIndex || 0, n = startValue || 0;;) {
			var nextTab = string.indexOf("\t", i);
			if (nextTab < 0 || nextTab >= end)
				return n + (end - i);
			n += nextTab - i;
			n += tabSize - (n % tabSize);
			i = nextTab + 1;
		}
	};

	// The inverse of countColumn -- find the offset that corresponds to
	// a particular column.
	function findColumn(string, goal, tabSize) {
		for (var pos = 0, col = 0;;) {
			var nextTab = string.indexOf("\t", pos);
			if (nextTab == -1) nextTab = string.length;
			var skipped = nextTab - pos;
			if (nextTab == string.length || col + skipped >= goal)
				return pos + Math.min(skipped, goal - col);
			col += nextTab - pos;
			col += tabSize - (col % tabSize);
			pos = nextTab + 1;
			if (col >= goal) return pos;
		}
	}

	var spaceStrs = [""];
	function spaceStr(n) {
		while (spaceStrs.length <= n)
			spaceStrs.push(lst(spaceStrs) + " ");
		return spaceStrs[n];
	}

	function lst(arr) { return arr[arr.length-1]; }

	var selectInput = function(node) { node.select(); };
	if (ios) // Mobile Safari apparently has a bug where select() is broken.
		selectInput = function(node) { node.selectionStart = 0; node.selectionEnd = node.value.length; };
	else if (ie) // Suppress mysterious IE10 errors
		selectInput = function(node) { try { node.select(); } catch(_e) {} };

	function indexOf(array, elt) {
		for (var i = 0; i < array.length; ++i)
			if (array[i] == elt) return i;
		return -1;
	}
	if ([].indexOf) indexOf = function(array, elt) { return array.indexOf(elt); };
	function map(array, f) {
		var out = [];
		for (var i = 0; i < array.length; i++) out[i] = f(array[i], i);
		return out;
	}
	if ([].map) map = function(array, f) { return array.map(f); };

	function createObj(base, props) {
		var inst;
		if (Object.create) {
			inst = Object.create(base);
		} else {
			var ctor = function() {};
			ctor.prototype = base;
			inst = new ctor();
		}
		if (props) copyObj(props, inst);
		return inst;
	};

	function copyObj(obj, target, overwrite) {
		if (!target) target = {};
		for (var prop in obj)
			if (obj.hasOwnProperty(prop) && (overwrite !== false || !target.hasOwnProperty(prop)))
				target[prop] = obj[prop];
		return target;
	}

	function bind(f) {
		var args = Array.prototype.slice.call(arguments, 1);
		return function(){return f.apply(null, args);};
	}

	var nonASCIISingleCaseWordChar = /[\u00df\u3040-\u309f\u30a0-\u30ff\u3400-\u4db5\u4e00-\u9fcc\uac00-\ud7af]/;
	var isWordCharBasic = CodeMirror.isWordChar = function(ch) {
		return /\w/.test(ch) || ch > "\x80" &&
			(ch.toUpperCase() != ch.toLowerCase() || nonASCIISingleCaseWordChar.test(ch));
	};
	function isWordChar(ch, helper) {
		if (!helper) return isWordCharBasic(ch);
		if (helper.source.indexOf("\\w") > -1 && isWordCharBasic(ch)) return true;
		return helper.test(ch);
	}

	function isEmpty(obj) {
		for (var n in obj) if (obj.hasOwnProperty(n) && obj[n]) return false;
		return true;
	}

	// Extending unicode characters. A series of a non-extending char +
	// any number of extending chars is treated as a single unit as far
	// as editing and measuring is concerned. This is not fully correct,
	// since some scripts/fonts/browsers also treat other configurations
	// of code points as a group.
	var extendingChars = /[\u0300-\u036f\u0483-\u0489\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u064b-\u065e\u0670\u06d6-\u06dc\u06de-\u06e4\u06e7\u06e8\u06ea-\u06ed\u0711\u0730-\u074a\u07a6-\u07b0\u07eb-\u07f3\u0816-\u0819\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0900-\u0902\u093c\u0941-\u0948\u094d\u0951-\u0955\u0962\u0963\u0981\u09bc\u09be\u09c1-\u09c4\u09cd\u09d7\u09e2\u09e3\u0a01\u0a02\u0a3c\u0a41\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a70\u0a71\u0a75\u0a81\u0a82\u0abc\u0ac1-\u0ac5\u0ac7\u0ac8\u0acd\u0ae2\u0ae3\u0b01\u0b3c\u0b3e\u0b3f\u0b41-\u0b44\u0b4d\u0b56\u0b57\u0b62\u0b63\u0b82\u0bbe\u0bc0\u0bcd\u0bd7\u0c3e-\u0c40\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62\u0c63\u0cbc\u0cbf\u0cc2\u0cc6\u0ccc\u0ccd\u0cd5\u0cd6\u0ce2\u0ce3\u0d3e\u0d41-\u0d44\u0d4d\u0d57\u0d62\u0d63\u0dca\u0dcf\u0dd2-\u0dd4\u0dd6\u0ddf\u0e31\u0e34-\u0e3a\u0e47-\u0e4e\u0eb1\u0eb4-\u0eb9\u0ebb\u0ebc\u0ec8-\u0ecd\u0f18\u0f19\u0f35\u0f37\u0f39\u0f71-\u0f7e\u0f80-\u0f84\u0f86\u0f87\u0f90-\u0f97\u0f99-\u0fbc\u0fc6\u102d-\u1030\u1032-\u1037\u1039\u103a\u103d\u103e\u1058\u1059\u105e-\u1060\u1071-\u1074\u1082\u1085\u1086\u108d\u109d\u135f\u1712-\u1714\u1732-\u1734\u1752\u1753\u1772\u1773\u17b7-\u17bd\u17c6\u17c9-\u17d3\u17dd\u180b-\u180d\u18a9\u1920-\u1922\u1927\u1928\u1932\u1939-\u193b\u1a17\u1a18\u1a56\u1a58-\u1a5e\u1a60\u1a62\u1a65-\u1a6c\u1a73-\u1a7c\u1a7f\u1b00-\u1b03\u1b34\u1b36-\u1b3a\u1b3c\u1b42\u1b6b-\u1b73\u1b80\u1b81\u1ba2-\u1ba5\u1ba8\u1ba9\u1c2c-\u1c33\u1c36\u1c37\u1cd0-\u1cd2\u1cd4-\u1ce0\u1ce2-\u1ce8\u1ced\u1dc0-\u1de6\u1dfd-\u1dff\u200c\u200d\u20d0-\u20f0\u2cef-\u2cf1\u2de0-\u2dff\u302a-\u302f\u3099\u309a\ua66f-\ua672\ua67c\ua67d\ua6f0\ua6f1\ua802\ua806\ua80b\ua825\ua826\ua8c4\ua8e0-\ua8f1\ua926-\ua92d\ua947-\ua951\ua980-\ua982\ua9b3\ua9b6-\ua9b9\ua9bc\uaa29-\uaa2e\uaa31\uaa32\uaa35\uaa36\uaa43\uaa4c\uaab0\uaab2-\uaab4\uaab7\uaab8\uaabe\uaabf\uaac1\uabe5\uabe8\uabed\udc00-\udfff\ufb1e\ufe00-\ufe0f\ufe20-\ufe26\uff9e\uff9f]/;
	function isExtendingChar(ch) { return ch.charCodeAt(0) >= 768 && extendingChars.test(ch); }

	// DOM UTILITIES

	function elt(tag, content, className, style) {
		var e = document.createElement(tag);
		if (className) e.className = className;
		if (style) e.style.cssText = style;
		if (typeof content == "string") e.appendChild(document.createTextNode(content));
		else if (content) for (var i = 0; i < content.length; ++i) e.appendChild(content[i]);
		return e;
	}

	var range;
	if (document.createRange) range = function(node, start, end) {
		var r = document.createRange();
		r.setEnd(node, end);
		r.setStart(node, start);
		return r;
	};
	else range = function(node, start, end) {
		var r = document.body.createTextRange();
		r.moveToElementText(node.parentNode);
		r.collapse(true);
		r.moveEnd("character", end);
		r.moveStart("character", start);
		return r;
	};

	function removeChildren(e) {
		for (var count = e.childNodes.length; count > 0; --count)
			e.removeChild(e.firstChild);
		return e;
	}

	function removeChildrenAndAdd(parent, e) {
		return removeChildren(parent).appendChild(e);
	}

	function contains(parent, child) {
		if (parent.contains)
			return parent.contains(child);
		while (child = child.parentNode)
			if (child == parent) return true;
	}

	function activeElt() { return document.activeElement; }
	// Older versions of IE throws unspecified error when touching
	// document.activeElement in some cases (during loading, in iframe)
	if (ie && ie_version < 11) activeElt = function() {
		try { return document.activeElement; }
		catch(e) { return document.body; }
	};

	function classTest(cls) { return new RegExp("\\b" + cls + "\\b\\s*"); }
	function rmClass(node, cls) {
		var test = classTest(cls);
		if (test.test(node.className)) node.className = node.className.replace(test, "");
	}
	function addClass(node, cls) {
		if (!classTest(cls).test(node.className)) node.className += " " + cls;
	}
	function joinClasses(a, b) {
		var as = a.split(" ");
		for (var i = 0; i < as.length; i++)
			if (as[i] && !classTest(as[i]).test(b)) b += " " + as[i];
		return b;
	}

	// WINDOW-WIDE EVENTS

	// These must be handled carefully, because naively registering a
	// handler for each editor will cause the editors to never be
	// garbage collected.

	function forEachCodeMirror(f) {
		if (!document.body.getElementsByClassName) return;
		var byClass = document.body.getElementsByClassName("CodeMirror");
		for (var i = 0; i < byClass.length; i++) {
			var cm = byClass[i].CodeMirror;
			if (cm) f(cm);
		}
	}

	var globalsRegistered = false;
	function ensureGlobalHandlers() {
		if (globalsRegistered) return;
		registerGlobalHandlers();
		globalsRegistered = true;
	}
	function registerGlobalHandlers() {
		// When the window resizes, we need to refresh active editors.
		var resizeTimer;
		on(window, "resize", function() {
			if (resizeTimer == null) resizeTimer = setTimeout(function() {
				resizeTimer = null;
				knownScrollbarWidth = null;
				forEachCodeMirror(onResize);
			}, 100);
		});
		// When the window loses focus, we want to show the editor as blurred
		on(window, "blur", function() {
			forEachCodeMirror(onBlur);
		});
	}

	// FEATURE DETECTION

	// Detect drag-and-drop
	var dragAndDrop = function() {
		// There is *some* kind of drag-and-drop support in IE6-8, but I
		// couldn't get it to work yet.
		if (ie && ie_version < 9) return false;
		var div = elt('div');
		return "draggable" in div || "dragDrop" in div;
	}();

	var knownScrollbarWidth;
	function scrollbarWidth(measure) {
		if (knownScrollbarWidth != null) return knownScrollbarWidth;
		var test = elt("div", null, null, "width: 50px; height: 50px; overflow-x: scroll");
		removeChildrenAndAdd(measure, test);
		if (test.offsetWidth)
			knownScrollbarWidth = test.offsetHeight - test.clientHeight;
		return knownScrollbarWidth || 0;
	}

	var zwspSupported;
	function zeroWidthElement(measure) {
		if (zwspSupported == null) {
			var test = elt("span", "\u200b");
			removeChildrenAndAdd(measure, elt("span", [test, document.createTextNode("x")]));
			if (measure.firstChild.offsetHeight != 0)
				zwspSupported = test.offsetWidth <= 1 && test.offsetHeight > 2 && !(ie && ie_version < 8);
		}
		if (zwspSupported) return elt("span", "\u200b");
		else return elt("span", "\u00a0", null, "display: inline-block; width: 1px; margin-right: -1px");
	}

	// Feature-detect IE's crummy client rect reporting for bidi text
	var badBidiRects;
	function hasBadBidiRects(measure) {
		if (badBidiRects != null) return badBidiRects;
		var txt = removeChildrenAndAdd(measure, document.createTextNode("A\u062eA"));
		var r0 = range(txt, 0, 1).getBoundingClientRect();
		if (r0.left == r0.right) return false;
		var r1 = range(txt, 1, 2).getBoundingClientRect();
		return badBidiRects = (r1.right - r0.right < 3);
	}

	// See if "".split is the broken IE version, if so, provide an
	// alternative way to split lines.
	var splitLines = CodeMirror.splitLines = "\n\nb".split(/\n/).length != 3 ? function(string) {
		var pos = 0, result = [], l = string.length;
		while (pos <= l) {
			var nl = string.indexOf("\n", pos);
			if (nl == -1) nl = string.length;
			var line = string.slice(pos, string.charAt(nl - 1) == "\r" ? nl - 1 : nl);
			var rt = line.indexOf("\r");
			if (rt != -1) {
				result.push(line.slice(0, rt));
				pos += rt + 1;
			} else {
				result.push(line);
				pos = nl + 1;
			}
		}
		return result;
	} : function(string){return string.split(/\r\n?|\n/);};

	var hasSelection = window.getSelection ? function(te) {
		try { return te.selectionStart != te.selectionEnd; }
		catch(e) { return false; }
	} : function(te) {
		try {var range = te.ownerDocument.selection.createRange();}
		catch(e) {}
		if (!range || range.parentElement() != te) return false;
		return range.compareEndPoints("StartToEnd", range) != 0;
	};

	var hasCopyEvent = (function() {
		var e = elt("div");
		if ("oncopy" in e) return true;
		e.setAttribute("oncopy", "return;");
		return typeof e.oncopy == "function";
	})();

	// KEY NAMES

	var keyNames = {3: "Enter", 8: "Backspace", 9: "Tab", 13: "Enter", 16: "Shift", 17: "Ctrl", 18: "Alt",
		19: "Pause", 20: "CapsLock", 27: "Esc", 32: "Space", 33: "PageUp", 34: "PageDown", 35: "End",
		36: "Home", 37: "Left", 38: "Up", 39: "Right", 40: "Down", 44: "PrintScrn", 45: "Insert",
		46: "Delete", 59: ";", 61: "=", 91: "Mod", 92: "Mod", 93: "Mod", 107: "=", 109: "-", 127: "Delete",
		173: "-", 186: ";", 187: "=", 188: ",", 189: "-", 190: ".", 191: "/", 192: "`", 219: "[", 220: "\\",
		221: "]", 222: "'", 63232: "Up", 63233: "Down", 63234: "Left", 63235: "Right", 63272: "Delete",
		63273: "Home", 63275: "End", 63276: "PageUp", 63277: "PageDown", 63302: "Insert"};
	CodeMirror.keyNames = keyNames;
	(function() {
		// Number keys
		for (var i = 0; i < 10; i++) keyNames[i + 48] = keyNames[i + 96] = String(i);
		// Alphabetic keys
		for (var i = 65; i <= 90; i++) keyNames[i] = String.fromCharCode(i);
		// Function keys
		for (var i = 1; i <= 12; i++) keyNames[i + 111] = keyNames[i + 63235] = "F" + i;
	})();

	// BIDI HELPERS

	function iterateBidiSections(order, from, to, f) {
		if (!order) return f(from, to, "ltr");
		var found = false;
		for (var i = 0; i < order.length; ++i) {
			var part = order[i];
			if (part.from < to && part.to > from || from == to && part.to == from) {
				f(Math.max(part.from, from), Math.min(part.to, to), part.level == 1 ? "rtl" : "ltr");
				found = true;
			}
		}
		if (!found) f(from, to, "ltr");
	}

	function bidiLeft(part) { return part.level % 2 ? part.to : part.from; }
	function bidiRight(part) { return part.level % 2 ? part.from : part.to; }

	function lineLeft(line) { var order = getOrder(line); return order ? bidiLeft(order[0]) : 0; }
	function lineRight(line) {
		var order = getOrder(line);
		if (!order) return line.text.length;
		return bidiRight(lst(order));
	}

	function lineStart(cm, lineN) {
		var line = getLine(cm.doc, lineN);
		var visual = visualLine(line);
		if (visual != line) lineN = lineNo(visual);
		var order = getOrder(visual);
		var ch = !order ? 0 : order[0].level % 2 ? lineRight(visual) : lineLeft(visual);
		return Pos(lineN, ch);
	}
	function lineEnd(cm, lineN) {
		var merged, line = getLine(cm.doc, lineN);
		while (merged = collapsedSpanAtEnd(line)) {
			line = merged.find(1, true).line;
			lineN = null;
		}
		var order = getOrder(line);
		var ch = !order ? line.text.length : order[0].level % 2 ? lineLeft(line) : lineRight(line);
		return Pos(lineN == null ? lineNo(line) : lineN, ch);
	}

	function compareBidiLevel(order, a, b) {
		var linedir = order[0].level;
		if (a == linedir) return true;
		if (b == linedir) return false;
		return a < b;
	}
	var bidiOther;
	function getBidiPartAt(order, pos) {
		bidiOther = null;
		for (var i = 0, found; i < order.length; ++i) {
			var cur = order[i];
			if (cur.from < pos && cur.to > pos) return i;
			if ((cur.from == pos || cur.to == pos)) {
				if (found == null) {
					found = i;
				} else if (compareBidiLevel(order, cur.level, order[found].level)) {
					if (cur.from != cur.to) bidiOther = found;
					return i;
				} else {
					if (cur.from != cur.to) bidiOther = i;
					return found;
				}
			}
		}
		return found;
	}

	function moveInLine(line, pos, dir, byUnit) {
		if (!byUnit) return pos + dir;
		do pos += dir;
		while (pos > 0 && isExtendingChar(line.text.charAt(pos)));
		return pos;
	}

	// This is needed in order to move 'visually' through bi-directional
	// text -- i.e., pressing left should make the cursor go left, even
	// when in RTL text. The tricky part is the 'jumps', where RTL and
	// LTR text touch each other. This often requires the cursor offset
	// to move more than one unit, in order to visually move one unit.
	function moveVisually(line, start, dir, byUnit) {
		var bidi = getOrder(line);
		if (!bidi) return moveLogically(line, start, dir, byUnit);
		var pos = getBidiPartAt(bidi, start), part = bidi[pos];
		var target = moveInLine(line, start, part.level % 2 ? -dir : dir, byUnit);

		for (;;) {
			if (target > part.from && target < part.to) return target;
			if (target == part.from || target == part.to) {
				if (getBidiPartAt(bidi, target) == pos) return target;
				part = bidi[pos += dir];
				return (dir > 0) == part.level % 2 ? part.to : part.from;
			} else {
				part = bidi[pos += dir];
				if (!part) return null;
				if ((dir > 0) == part.level % 2)
					target = moveInLine(line, part.to, -1, byUnit);
				else
					target = moveInLine(line, part.from, 1, byUnit);
			}
		}
	}

	function moveLogically(line, start, dir, byUnit) {
		var target = start + dir;
		if (byUnit) while (target > 0 && isExtendingChar(line.text.charAt(target))) target += dir;
		return target < 0 || target > line.text.length ? null : target;
	}

	// Bidirectional ordering algorithm
	// See http://unicode.org/reports/tr9/tr9-13.html for the algorithm
	// that this (partially) implements.

	// One-char codes used for character types:
	// L (L):   Left-to-Right
	// R (R):   Right-to-Left
	// r (AL):  Right-to-Left Arabic
	// 1 (EN):  European Number
	// + (ES):  European Number Separator
	// % (ET):  European Number Terminator
	// n (AN):  Arabic Number
	// , (CS):  Common Number Separator
	// m (NSM): Non-Spacing Mark
	// b (BN):  Boundary Neutral
	// s (B):   Paragraph Separator
	// t (S):   Segment Separator
	// w (WS):  Whitespace
	// N (ON):  Other Neutrals

	// Returns null if characters are ordered as they appear
	// (left-to-right), or an array of sections ({from, to, level}
	// objects) in the order in which they occur visually.
	var bidiOrdering = (function() {
		// Character types for codepoints 0 to 0xff
		var lowTypes = "bbbbbbbbbtstwsbbbbbbbbbbbbbbssstwNN%%%NNNNNN,N,N1111111111NNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNNNLLLLLLLLLLLLLLLLLLLLLLLLLLNNNNbbbbbbsbbbbbbbbbbbbbbbbbbbbbbbbbb,N%%%%NNNNLNNNNN%%11NLNNN1LNNNNNLLLLLLLLLLLLLLLLLLLLLLLNLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLN";
		// Character types for codepoints 0x600 to 0x6ff
		var arabicTypes = "rrrrrrrrrrrr,rNNmmmmmmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmrrrrrrrnnnnnnnnnn%nnrrrmrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrmmmmmmmmmmmmmmmmmmmNmmmm";
		function charType(code) {
			if (code <= 0xf7) return lowTypes.charAt(code);
			else if (0x590 <= code && code <= 0x5f4) return "R";
			else if (0x600 <= code && code <= 0x6ed) return arabicTypes.charAt(code - 0x600);
			else if (0x6ee <= code && code <= 0x8ac) return "r";
			else if (0x2000 <= code && code <= 0x200b) return "w";
			else if (code == 0x200c) return "b";
			else return "L";
		}

		var bidiRE = /[\u0590-\u05f4\u0600-\u06ff\u0700-\u08ac]/;
		var isNeutral = /[stwN]/, isStrong = /[LRr]/, countsAsLeft = /[Lb1n]/, countsAsNum = /[1n]/;
		// Browsers seem to always treat the boundaries of block elements as being L.
		var outerType = "L";

		function BidiSpan(level, from, to) {
			this.level = level;
			this.from = from; this.to = to;
		}

		return function(str) {
			if (!bidiRE.test(str)) return false;
			var len = str.length, types = [];
			for (var i = 0, type; i < len; ++i)
				types.push(type = charType(str.charCodeAt(i)));

			// W1. Examine each non-spacing mark (NSM) in the level run, and
			// change the type of the NSM to the type of the previous
			// character. If the NSM is at the start of the level run, it will
			// get the type of sor.
			for (var i = 0, prev = outerType; i < len; ++i) {
				var type = types[i];
				if (type == "m") types[i] = prev;
				else prev = type;
			}

			// W2. Search backwards from each instance of a European number
			// until the first strong type (R, L, AL, or sor) is found. If an
			// AL is found, change the type of the European number to Arabic
			// number.
			// W3. Change all ALs to R.
			for (var i = 0, cur = outerType; i < len; ++i) {
				var type = types[i];
				if (type == "1" && cur == "r") types[i] = "n";
				else if (isStrong.test(type)) { cur = type; if (type == "r") types[i] = "R"; }
			}

			// W4. A single European separator between two European numbers
			// changes to a European number. A single common separator between
			// two numbers of the same type changes to that type.
			for (var i = 1, prev = types[0]; i < len - 1; ++i) {
				var type = types[i];
				if (type == "+" && prev == "1" && types[i+1] == "1") types[i] = "1";
				else if (type == "," && prev == types[i+1] &&
					(prev == "1" || prev == "n")) types[i] = prev;
				prev = type;
			}

			// W5. A sequence of European terminators adjacent to European
			// numbers changes to all European numbers.
			// W6. Otherwise, separators and terminators change to Other
			// Neutral.
			for (var i = 0; i < len; ++i) {
				var type = types[i];
				if (type == ",") types[i] = "N";
				else if (type == "%") {
					for (var end = i + 1; end < len && types[end] == "%"; ++end) {}
					var replace = (i && types[i-1] == "!") || (end < len && types[end] == "1") ? "1" : "N";
					for (var j = i; j < end; ++j) types[j] = replace;
					i = end - 1;
				}
			}

			// W7. Search backwards from each instance of a European number
			// until the first strong type (R, L, or sor) is found. If an L is
			// found, then change the type of the European number to L.
			for (var i = 0, cur = outerType; i < len; ++i) {
				var type = types[i];
				if (cur == "L" && type == "1") types[i] = "L";
				else if (isStrong.test(type)) cur = type;
			}

			// N1. A sequence of neutrals takes the direction of the
			// surrounding strong text if the text on both sides has the same
			// direction. European and Arabic numbers act as if they were R in
			// terms of their influence on neutrals. Start-of-level-run (sor)
			// and end-of-level-run (eor) are used at level run boundaries.
			// N2. Any remaining neutrals take the embedding direction.
			for (var i = 0; i < len; ++i) {
				if (isNeutral.test(types[i])) {
					for (var end = i + 1; end < len && isNeutral.test(types[end]); ++end) {}
					var before = (i ? types[i-1] : outerType) == "L";
					var after = (end < len ? types[end] : outerType) == "L";
					var replace = before || after ? "L" : "R";
					for (var j = i; j < end; ++j) types[j] = replace;
					i = end - 1;
				}
			}

			// Here we depart from the documented algorithm, in order to avoid
			// building up an actual levels array. Since there are only three
			// levels (0, 1, 2) in an implementation that doesn't take
			// explicit embedding into account, we can build up the order on
			// the fly, without following the level-based algorithm.
			var order = [], m;
			for (var i = 0; i < len;) {
				if (countsAsLeft.test(types[i])) {
					var start = i;
					for (++i; i < len && countsAsLeft.test(types[i]); ++i) {}
					order.push(new BidiSpan(0, start, i));
				} else {
					var pos = i, at = order.length;
					for (++i; i < len && types[i] != "L"; ++i) {}
					for (var j = pos; j < i;) {
						if (countsAsNum.test(types[j])) {
							if (pos < j) order.splice(at, 0, new BidiSpan(1, pos, j));
							var nstart = j;
							for (++j; j < i && countsAsNum.test(types[j]); ++j) {}
							order.splice(at, 0, new BidiSpan(2, nstart, j));
							pos = j;
						} else ++j;
					}
					if (pos < i) order.splice(at, 0, new BidiSpan(1, pos, i));
				}
			}
			if (order[0].level == 1 && (m = str.match(/^\s+/))) {
				order[0].from = m[0].length;
				order.unshift(new BidiSpan(0, 0, m[0].length));
			}
			if (lst(order).level == 1 && (m = str.match(/\s+$/))) {
				lst(order).to -= m[0].length;
				order.push(new BidiSpan(0, len - m[0].length, len));
			}
			if (order[0].level != lst(order).level)
				order.push(new BidiSpan(order[0].level, len, len));

			return order;
		};
	})();

	// THE END

	CodeMirror.version = "4.3.0";

	return CodeMirror;
});
